# Colour changing effect in Rev's footer
**URL:** https://forum.kirupa.com/t/colour-changing-effect-in-revs-footer/34403
**Category:** flash
**Created:** [November 1, 2003, 6:38pm UTC](https://forum.kirupa.com/t/colour-changing-effect-in-revs-footer/34403 "2003-11-01T18:38:33Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Ranoka](https://forum.kirupa.com/u/Ranoka)
#### Post date: [November 1, 2003, 6:38pm UTC](https://forum.kirupa.com/t/colour-changing-effect-in-revs-footer/34403/1 "2003-11-01T18:38:33Z")
Hi all,
I was just wondering how Rev did the colour changing effect in his current footer?
Reminds me of my ZX Spectrum games, and I wan’t to play around with this effect.
I assume there is actionscript code involved in this effect?
Cheers 🙂
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### Author:  [@system](https://forum.kirupa.com/u/system)
#### Post date: [November 1, 2003, 7:06pm UTC](https://forum.kirupa.com/t/colour-changing-effect-in-revs-footer/34403/2 "2003-11-01T19:06:30Z")
I got it from a thread that Ilyas made, where he stated that he ‘borrowed’ it from Bit-101’s site.
so, you can do a search for it here, or go straight to the source, Bit-101 …
Rev 
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### Author:  [@system](https://forum.kirupa.com/u/system)
#### Post date: [November 2, 2003, 11:10am UTC](https://forum.kirupa.com/t/colour-changing-effect-in-revs-footer/34403/3 "2003-11-02T11:10:26Z")
Cycling colors tutorial: :beam:
First, create a dot:
```auto
this.createEmptyMovieClip ( "myClip", 0 ) ;
myClip.lineStyle ( 30, 0, 100 ) ;
myClip.lineTo ( .45, .15 ) ;
```
Then create the color cycle:
```auto
// Create a color object corresponding to the clip you want to apply setRGB to
myClip.colorClip = new Color ( myClip ) ;
myClip.onEnterFrame = function () {
var r = 128 * ( 1 + Math.cos ( ra += .03 ) ) ;
var g = 128 * ( 1 + Math.cos ( rg += .05 ) ) ;
var b = 128 * ( 1 + Math.cos ( rb += .01 ) ) ;
var myColor = r << 16 | g << 8 | b ;
this.colorClip.setRGB ( myColor ) ;
}
```
The tricky part is in the onEnterFrame.
[FONT=courier new]var r = 128 \* ( 1 + Math.cos ( ra += .03 ) ) ;[/FONT]
for instance, will return a number between 0 and 256, which is pretty much what we want since color components (green, red and blue) go from 0 to 255 (0 to FF in hexadecimal), 0 being ‘no color’ and 255 (or FF) being ‘full color’.
The Math.cos part does the cycling, because that function (just like Math.sin) returns cycling values between -1 and 1 (it’s a circular function).
Once we’ve calculated the 3 components of our color (r, g, b), we put them together with this very nice line:
[FONT=courier new]var myColor = r \<\< 16 | g \<\< 8 | b ;[/FONT]
It has to be in this order: Red, then Green, and then Blue, as in RGB. The \<\< and | operators are bitwise operators, and they allow you to shift your color values properly, and then stick them together.
Tadaaa!! Finished 🙂
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### Author:  [@system](https://forum.kirupa.com/u/system)
#### Post date: [November 13, 2003, 11:37pm UTC](https://forum.kirupa.com/t/colour-changing-effect-in-revs-footer/34403/4 "2003-11-13T23:37:52Z")
Thanks Ilyas!
Sorry I didn’t thank you earlier, but I only just checked the thread.
I’ve just started learning Actionscript. My tutor just the other day showed me cycles using cos and sin, so I understand the code!
Thanks again! I’m going to have a play around now 🙂