Rainbow
- Task
- Print out the word 'RAINBOW' to the screen with every character being a different color of the rainbow.
ALGOL 68
Generates an SVG document, you can redirect the output to a .svg file and open it in a browser or other SVG viewer.
BEGIN # generate SVG to show the word RAINBOW in the colours of the spectrum #
PROC max = ( INT a, b )INT: IF a < b THEN b ELSE a FI;
STRING text = "RAINBOW";
[]STRING colour = ( "red", "orange", "yellow", "green", "blue", "indigo", "violet" );
INT c len = ( UPB colour - LWB colour ) + 1; # number of colours #
INT x := 30;
INT y = 30;
print( ( "<svg xmlns='http://www.w3.org/2000/svg' width='"
, whole( ( c len * 20 ) + 60, 0 ), "' "
, "height='50' style='font:bold 30px monospace'>", newline
, " <rect width='100%' height='100%' fill='grey'/>", newline
)
);
FOR i FROM LWB text TO UPB text DO
STRING c name = colour[ max( 1, i MOD ( c len + 1 ) ) ];
print( ( " <text x='", whole( x, 0 ), "' y='", whole( y, 0 ), "' " ) );
print( ( "fill='", c name, "' stroke='", c name, "'>", text[ i ], "</text>", newline ) );
x +:= 20
OD;
print( ( "</svg>", newline ) )
END
- Output:
<svg xmlns='http://www.w3.org/2000/svg' width='200' height='50' style='font:bold 30px monospace'> <rect width='100%' height='100%' fill='grey'/> <text x='30' y='30' fill='red' stroke='red'>R</text> <text x='50' y='30' fill='orange' stroke='orange'>A</text> <text x='70' y='30' fill='yellow' stroke='yellow'>I</text> <text x='90' y='30' fill='green' stroke='green'>N</text> <text x='110' y='30' fill='blue' stroke='blue'>B</text> <text x='130' y='30' fill='indigo' stroke='indigo'>O</text> <text x='150' y='30' fill='violet' stroke='violet'>W</text> </svg>
Arturo
loop [
#red "R"
#orange "A"
#yellow "I"
#green "N"
#blue "B"
#indigo "O"
#violet "W"
] [c l] -> prints color c l
BASIC
AmigaBASIC

SCREEN 1,640,200,3,2
WINDOW 2,"Rainbow text",(0,10)-(320,50),15,1
LOCATE 3,18
s$="RAINBOW"
PALETTE 0,.8,.8,.8
FOR i=1 TO 7
READ r,g,b
PALETTE i,r,g,b
COLOR i
PRINT MID$(s$,i,1);
NEXT
WHILE INKEY$=""
WEND
SCREEN CLOSE 1
DATA .93,.11,.14
DATA 1,.5,.15
DATA 1,.95,0
DATA .13,.69,.3
DATA 0,.64,.91
DATA .25,.28,.8
DATA .64,.29,.65
Applesoft BASIC
1 GR : DEF FN C(I) = ASC ( MID$ (A$,I)) - 58: FOR C = 1 TO 7: READ A$: COLOR= FN C(1): FOR I = 2 TO LEN (A$) STEP 3: VLIN FN C(I), FN C(I + 1) AT FN C(I + 2): NEXT I,C
2 DATA"K?E?@BA??@CC@DEA",S@EC??DCCD@EE,W?EG,V?EI@AJBCK?EL,Q?EN??OBBOEEO@APCDP,L@DR??SEES@DT,M?EVCDWABXCDY?EZ
Aquarius BASIC

10 PRINT CHR$(11)
20 PRINT "RAINBOW"
30 CS=13393
40 FOR I=0 TO 6
50 READ C
60 C=16*C+7
70 POKE CS+I,C
80 NEXT
90 DATA 1,3,2,6,4,10,5
BASIC256
dim colors$(6)
colors$ = {red, orange, yellow, green, blue, darkblue, cyan}
clg
s$ = "RAINBOW"
for i = 1 to length(s$)
color colors$[i-1]
text i*8,150, mid(s$,i,1)
next i
BBC BASIC

10 MODE 2
20 S$="RAINBOW"
30 FOR I=1 to 7
40 READ C
50 COLOUR C
60 PRINT MID$(S$,I,1);
70 NEXT
80 PRINT
90 DATA 1,2,3,7,6,4,5
Chipmunk Basic
100 graphics 0
110 dim colors(6,6,6)
120 data 255,0,0,255,128,0,255,255,0,0,255,0,0,0,255,75,0,130,128,0,255
130 s$ = "RAINBOW"
140 for i = 1 to 7
150 read a,b,c
160 graphics color a,b,c
170 graphics moveto i*10,10
180 graphics text mid$(s$,i,1);
190 next i
200 end
Commodore BASIC

10 S$="RAINBOW":POKE 53281,1
20 FOR I=1 TO 7
30 READ C:POKE 646,C
40 PRINT MID$(S$,I,1);
50 NEXT
60 DATA 2,8,7,5,3,6,4
FreeBASIC

Dim As Integer colors(6, 2) => { _
{255, 0, 0}, _ ' red
{255, 128, 0}, _ ' orange
{255, 255, 0}, _ ' yellow
{ 0, 255, 0}, _ ' green
{ 0, 0, 255}, _ ' blue
{75, 0, 130}, _ ' indigo
{128, 0, 255}} _ ' violet
Cls
Dim As String s = "RAINBOW"
For i As Byte = 1 To Len(s)
Color Rgb(colors(i,2),colors(i,2),colors(i,2))
Print Mid(s, i, 1);
Next i
Sleep
GW-BASIC
10 CLS
20 DATA 4,6,14,2,1,11,13
30 S$ = "RAINBOW"
40 FOR I = 1 TO 7
50 READ C
60 COLOR C
70 PRINT MID$(S$, I, 1);
80 NEXT I
90 END
Locomotive Basic

10 mode 0:ink 0,10:locate 7,10:s$="RAINBOW"
20 for i=1 to 7
30 read col:ink i,col:pen i
40 print mid$(s$,i,1);
50 next
60 goto 60
70 data 6,15,24,18,2,5,8
True BASIC
CLEAR
DATA 4, 6, 14, 2, 1, 11, 13
LET s$ = "RAINBOW"
FOR i = 1 to 7
READ c
SET COLOR c
PRINT (s$)[i:i+1-1];
NEXT i
END
ZX Spectrum Basic

10 PAPER 0
20 LET s$="RAINBOW"
30 FOR i=1 TO 7
40 READ c
50 INK c
60 PRINT s$(i TO i);
70 NEXT i
80 PAPER 7
90 DATA 2,4,6,7,5,1,3
C
#include <stdio.h>
int main() {
int i, clrs[7][3] = {
{255, 0, 0}, // red
{255, 128, 0}, // orange
{255, 255, 0}, // yellow
{ 0, 255, 0}, // green
{ 0, 0, 255}, // blue
{ 75, 0, 130}, // indigo
{128, 0, 255}, // violet
};
const char *s = "RAINBOW";
for (i = 0; i < 7; ++i) {
printf("\x1B[38;2;%d;%d;%dm%c", clrs[i][0], clrs[i][1], clrs[i][2], s[i]);
}
printf("\n");
return 0;
}
- Output:
C++
#include <cstdint>
#include <iostream>
#include <string>
#include <vector>
int main() {
// ANSI escape code constants for foreground text colours
const std::string RED = "\u001B[38;2;255;0;0m";
const std::string ORANGE = "\u001B[38;2;255;128;0m";
const std::string YELLOW = "\u001B[38;2;255;255;0m";
const std::string GREEN = "\u001B[38;2;0;255;0m";
const std::string BLUE = "\u001B[38;2;0;0;255m";
const std::string INDIGO = "\u001B[38;2;75;0;130m";
const std::string VIOLET = "\u001B[38;2;128;0;255m";
// ANSI escape code constant to reset the terminal to its default values
const std::string RESET = "\u001B[0m";
const std::vector<std::string> colours = { RED, ORANGE, YELLOW, GREEN, BLUE, INDIGO, VIOLET };
const std::string rainbow = "RAINBOW";
for ( uint32_t i = 0; i < 7; ++i ) {
std::cout << colours[i] << rainbow[i];
}
std::cout << RESET << std::endl;
}
- Output:
Dart
import 'dart:io';
void main() {
const rainbow = 'RAINBOW';
const spectrum = [
[255, 0, 0], // red
[255, 165, 0], // orange
[255, 255, 0], // yellow
[0, 128, 0], // green
[0, 0, 255], // blue
[75, 0, 130], // indigo
[238, 130, 238], // violet
];
for (int i = 0; i < rainbow.length; i++) {
final red = spectrum[i][0];
final green = spectrum[i][1];
final blue = spectrum[i][2];
stdout.write('\x1B[38;2;${red};${green};${blue}m${rainbow[i]}\x1B[0m');
}
}
EasyLang
s$ = "RAINBOW"
cols[] = [ 900 950 990 090 009 306 509 ]
textsize 15
background 000
clear
for i to 7
color cols[i]
move i * 11.5 60
text substr s$ i 1
.
Factor
USING: colors grouping hashtables io.styles qw sequences ui
ui.gadgets.panes ;
"RAINBOW" 1 group
qw{ red orange yellow green blue indigo violet } [
[ named-color foreground associate format ] 2each
] make-pane "Rainbow" open-window
- Output:

FutureBasic
Requires FB 7.0.31 or newer to compile macOS app.
_window = 1
begin enum 1
_txtField
end enum
CFMutableAttributedStringRef local fn ColoredCharacters( string as CFStringRef )
CFMutableAttributedStringRef aString = fn MutableAttributedStringWithString( string )
for int i = 0 to len(string) -1
CGFloat red = rnd(256) / 255.0
CGFloat green = rnd(256) / 255.0
CGFloat blue = rnd(256) / 255.0
ColorRef randomColor = fn ColorWithSRGB( red, green, blue, 1.0 )
MutableAttributedStringSetForegroundColorInRange( aString, randomColor, fn RangeMake( i, 1 ) )
next
MutableAttributedStringSetAlignment( aString, NSTextAlignmentCenter )
MutableAttributedStringSetFontWithName( aString, @"Times Bold", 60.0 )
end fn = aString
void local fn BuildWindow
CGRect r = fn CGRectMake( 0, 0, 340, 100 )
window _window, @"Colored Characters", r, NSWindowStyleMaskTitled + NSWindowStyleMaskClosable
WindowSetBackgroundColor( _window, fn ColorWhite )
r = fn CGRectMake( 0, 25, 340, 60 )
textfield _txtField, YES, ,r, _window
TextFieldSetBezeled( _txtField, NO )
TextFieldSetBordered( _txtField, NO )
TextFieldSetDrawsBackground( _txtField, NO )
TextFieldSetPlaceholderAttributedString( _txtField, fn ColoredCharacters( @"RAINBOW" ) )
end fn
random
fn BuildWindow
HandleEvents
- Output:
Go
package main
import "fmt"
func main() {
clrs := [7][3]int{
{255, 0, 0}, // red
{255, 128, 0}, // orange
{255, 255, 0}, // yellow
{0, 255, 0}, // green
{0, 0, 255}, // blue
{75, 0, 130}, // indigo
{128, 0, 255}, // violet
}
s := "RAINBOW"
for i := 0; i < 7; i++ {
fmt.Printf("\x1B[38;2;%d;%d;%dm%c", clrs[i][0], clrs[i][1], clrs[i][2], s[i])
}
fmt.Println()
}
- Output:
As C example.
HTML
<!DOCTYPE html>
<html>
<head>
<title>Text in Multiple Colors (No Spaces)</title>
</head>
<body>
<p>
<span style="color: red">R</span><span style="color: orange">A</span><span style="color: yellow">I</span><span style="color: green">N</span><span style="color: blue">B</span><span style="color: indigo">O</span><span style="color: violet">W</span>
</p>
</body>
</html>
Java
import java.util.List;
public final class Rainbow {
public static void main(String[] args) {
// ANSI escape code constants for foreground text colours
final String RED = "\u001B[38;2;255;0;0m";
final String ORANGE = "\u001B[38;2;255;128;0m";
final String YELLOW = "\u001B[38;2;255;255;0m";
final String GREEN = "\u001B[38;2;0;255;0m";
final String BLUE = "\u001B[38;2;0;0;255m";
final String INDIGO = "\u001B[38;2;75;0;130m";
final String VIOLET = "\u001B[38;2;128;0;255m";
// ANSI escape code constant to reset the terminal to its default values
final String RESET = "\u001B[0m";
List<String> colours = List.of( RED, ORANGE, YELLOW, GREEN, BLUE, INDIGO, VIOLET );
String rainbow = "RAINBOW";
for ( int i = 0; i < 7; i++ ) {
System.out.print(colours.get(i) + rainbow.charAt(i));
}
System.out.println(RESET);
}
}
- Output:
jq
The following assumes the terminal supports the ANSI RGB codes, and has been tested using iTerm2.
def colors: [
[255, 0, 0], # red
[255, 128, 0], # orange
[255, 255, 0], # yellow
[ 0, 255, 0], # green
[ 0, 0, 255], # blue
[ 75, 0, 130], # indigo
[128, 0, 255] # violet
];
def rainbow($s):
# ;38 is the extended foreground color code
# ;2 indicates RGB digits follow
def e: "\u001B"; # ESCAPE
reduce range(0; $s|length) as $j ("";
($j % 7) as $i
| . + "\(e)[38;2;\(colors[$i][0]);\(colors[$i][1]);\(colors[$i][2])m\($s[$i:$i+1])" )
+ "\(e)[0m";
rainbow("RAINBOW")
Invocation: jq -nr -f rainbow.jq
Julia
using Crayons
for (letter, color) in [("R", crayon"red"), ("A", crayon"ff7f00"),
("I", crayon"yellow"), ("N", crayon"green"),
("B", crayon"blue"), ("O", crayon"4b0082"), ("W", crayon"7f00ff")]
print(color, letter, " ");
end

M2000 Interpreter
M2000 Interpreter has own console which we can draw on it.
FORM 20, 16
MODULE CHECK {
MODULE RAINBOW{
OLDPEN=PEN
CLS #1F3F1F, 0
FLUSH ' empty stack
DATA #FF0000, color(255, 128,0),14, 3, #2F2FFF, color(135,64,210), #7F1FAA
LET s$ = "RAINBOW"
FOR i = 1 to 7
READ c
PEN c
PRINT MID$(s$,i,1);
NEXT i
PRINT
PEN OLDPEN
END
}
RAINBOW
DRAWING {
RAINBOW
} AS DRW1 ' THIS IS AN EMF DATA IN RAM FILE
MOVE 6000,6000
' DRAW GRAPH WIDH 6000 TWIPS, HEIGHT CALCULATING AUTOMATIC, 30 DEGREE SLOPE
IMAGE DRW1, 6000,,30
PEN 11 {WIDTH 10 {CIRCLE 4000}}
}
CHECK
PUSH KEY$:DROP
FORM 80, 38
- Output:

Perl
#!/usr/bin/perl
use strict; # https://rosettacode.org/wiki/Rainbow
use warnings;
use List::AllUtils qw( zip_by );
print zip_by { "\e[38;2;$_[1]m$_[0]\e[m" } [ split //, 'RAINBOW' ],
[qw( 255;0;0 255;128;0 255;255;0 0;255;0 0;0;255 75;0;130 128;0;255 )];
print "\n";
Phix
with javascript_semantics
requires("1.0.6")
include xpGUI.e
constant rainbow = {{"R",XPG_RED},
{"A",XPG_ORANGE},
{"I",XPG_YELLOW},
{"N",XPG_GREEN},
{"B",XPG_BLUE},
{"O",XPG_INDIGO},
{"W",XPG_PURPLE}}
function get_data(integer idx)
return iff(idx<=0?1:rainbow)
end function
gdx list = gList(get_data,"=BGCLR",{#F0F0F0}),
vbox = gVbox({list},`MARGIN=10`),
dialog = gDialog(vbox,"Rainbow",`SIZE=240x62`)
gShow(dialog)
gMainLoop()
- Output:

Python
Colored
from colored import Fore, Style
red: str = f'{Fore.rgb(255, 0, 0)}'
orange: str = f'{Fore.rgb(255, 128, 0)}'
yellow: str = f'{Fore.rgb(255, 255, 0)}'
green: str = f'{Fore.rgb(0, 255, 0)}'
blue: str = f'{Fore.rgb(0, 0, 255)}'
indigo: str = f'{Fore.rgb(75, 0, 130)}'
violet: str = f'{Fore.rgb(128, 0, 255)}'
print(f'{red}R{Style.reset}' + f'{orange}A{Style.reset}' + f'{yellow}I{Style.reset}' + f'{green}N{Style.reset}' + f'{blue}B{Style.reset}' + f'{indigo}O{Style.reset}' + f'{violet}W{Style.reset}')
- Output:
RAINBOW
Quackery
[ char m join
$ /
print(("\033["+string_from_stack()),end='')
/ python ] is colour ( $ --> )
[ $ "31" colour ] is red ( --> )
[ $ "38;5;208" colour ] is orange ( --> )
[ $ "33" colour ] is yellow ( --> )
[ $ "32" colour ] is green ( --> )
[ $ "34" colour ] is blue ( --> )
[ $ "38;5;54" colour ] is indigo ( --> )
[ $ "35" colour ] is violet ( --> )
[ $ "30" colour ] is black ( --> )
$ "RAINBOW"
' [ red orange yellow green blue indigo violet ]
witheach [ do behead emit ]
drop
black
- Output:

Raku
use Color::Names:api<2>;
use Color::Names::X11 :colors;
for 'RAINBOW',
'Another phrase that happens to contain the word "Rainbow".'
-> $rainbow-text {
for $rainbow-text.comb Z, flat(<red orange yellow green blue indigo violet> xx *) -> ($l, $c) {
print "\e[38;2;{COLORS{"{$c}-X11"}<rgb>.join(';')}m$l\e[0"
}
say '';
}
- Output:
Displayed here as HTML as ANSI colors don't show up on web interfaces.
Another phrase that happens to contain the word "Rainbow".
SVG
(this is also the output from the Algol 68 sample)
<svg xmlns='http://www.w3.org/2000/svg' width='200' height='50' style='font:bold 30px monospace'>
<rect width='100%' height='100%' fill='grey'/>
<text x='30' y='30' fill='red' stroke='red'>R</text>
<text x='50' y='30' fill='orange' stroke='orange'>A</text>
<text x='70' y='30' fill='yellow' stroke='yellow'>I</text>
<text x='90' y='30' fill='green' stroke='green'>N</text>
<text x='110' y='30' fill='blue' stroke='blue'>B</text>
<text x='130' y='30' fill='indigo' stroke='indigo'>O</text>
<text x='150' y='30' fill='violet' stroke='violet'>W</text>
</svg>
UNIX Shell
echo "$(tput setaf 1)R $(tput setaf 7)A $(tput setaf 3)I $(tput setaf 2)N $(tput setaf 4)B $(tput setaf 6)O $(tput setaf 5)W $(tput sgr0)"
— Ken McLeod
Wren
var colors = [
[255, 0, 0], // red
[255, 128, 0], // orange
[255, 255, 0], // yellow
[ 0, 255, 0], // green
[ 0, 0, 255], // blue
[ 75, 0, 130], // indigo
[128, 0, 255] // violet
]
var s = "RAINBOW"
for (i in 0..6) {
var fore = "\e[38;2;%(colors[i][0]);%(colors[i][1]);%(colors[i][2])m"
System.write("%(fore)%(s[i])")
}
System.print()
- Output:
X86 Assembly
Twenty-six byte executable program. Output is same as XPL0. Assemble with: tasm; tlink /t
0000 .model tiny
0000 .code
org 100h
;MS-DOS loads .com files with registers set this way:
; ax=0, bx=0, cx=00FFh, dx=cs, si=0100h, di=-2, bp=09xx, sp=-2, es=ds=cs=ss
;The direction flag (d) is clear (incrementing).
0100 52 41 49 4E 42 4F 57 start: db "RAINBOW" ;executed as code shown below
;push dx inc cx dec cx DEC SI inc dx dec di push di
0107 B0 13 mov al, 13h ;call BIOS to set graphic mode 13h (ah=0)
0109 CD 10 int 10h ; 320x200 with 256 colors
010B B3 1E mov bl, 32-2 ;base of rainbow colors
010D B1 08 mov cl, 1+7 ;number of characters to display + null in PSP
010F B4 0E mov ah, 0Eh ;write character in teletype mode
0111 AC rb10: lodsb ;fetch char to write: al:= ds:[si++]
0112 CD 10 int 10h
0114 43 inc bx ;next color
0115 43 inc bx
0116 E2 F9 loop rb10 ;loop for all 1+7 characters (cx--)
0118 EB FE jmp $ ;lock up
end start
XPL0

The Raspberry Pi versions of the language require a graphic mode for colored text (unlike the MS-DOS versions), but they compensate by supporting this unusual string indexing (which only works with the interpreted MS-DOS version).
char I;
[SetVid($13); \set 320x200x8 VGA graphics
for I:= 0 to 6 do
[Attrib(32+I+I); \set color attribute
ChOut(6, I("RAINBOW "));
];
]
Zig
const std = @import("std");
pub fn main() void {
const clrs = [7][3]u8{
[_]u8{255, 0, 0}, // red
[_]u8{255, 128, 0}, // orange
[_]u8{255, 255, 0}, // yellow
[_]u8{0, 255, 0}, // green
[_]u8{0, 0, 255}, // blue
[_]u8{75, 0, 130}, // indigo
[_]u8{128, 0, 255}, // violet
};
const s = "RAINBOW";
for(0..7) |i| {
std.debug.print("\x1B[38;2;{d};{d};{d}m{c}", .{clrs[i][0], clrs[i][1], clrs[i][2], s[i]});
}
std.debug.print("\n", .{});
}
- Output:
- Draft Programming Tasks
- ALGOL 68
- Arturo
- BASIC
- AmigaBASIC
- Applesoft BASIC
- Aquarius BASIC
- BASIC256
- BBC BASIC
- Chipmunk Basic
- Commodore BASIC
- FreeBASIC
- GW-BASIC
- Locomotive Basic
- True BASIC
- ZX Spectrum Basic
- C
- C++
- Dart
- EasyLang
- Factor
- FutureBasic
- Go
- HTML
- Java
- Jq
- Julia
- M2000 Interpreter
- Perl
- Phix
- Phix/xpGUI
- Python
- Quackery
- Raku
- SVG
- UNIX Shell
- Wren
- X86 Assembly
- XPL0
- Zig