• Adobe After Effects Expressions

  Switching between an array of colors

  Posted by Thomas Hannen on March 1, 2016 at 4:54 pm

  I have a set of 14 different colors stored as RGBA, or Hex values.
  I would like to be able to apply those colors to a solid, and switch between them using a slider control.

  I’ve found a way to do this using Hue angles, but not for RGBA or Hex values. If I name each of the arrays with a number in the name, can I append that number to a string, then call it in the expression somehow?

  mycolor1 = [81,45,10,255];
mycolor2 = [38,184,82,255];
mycolor3 = [255,157,150,255];
mycolor4 = [19,23,148,255];
mycolor5 = [119,241,225,255];
mycolor6 = [255,59,212,255];
mycolor7 = [44,134,120,255];
mycolor8 = [255,89,10,255];
mycolor9 = [235,213,8,255];
mycolor10 = [236,39,34,255];
mycolor11 = [228,212,136,255];
mycolor12 = [186,38,138,255];
mycolor13 = [255,142,144,255];
mycolor14 = [48,205,187,255];

  mynumber = thisComp.layer("Null 3").effect("choosecolor")("Slider");

  finalstring = 'mycolor' + mynumber +'[0]/255'; // this doesn't work!

  var r = mycolor2[0]/255;
  var g = mycolor2[1]/255;
  var b = mycolor2[2]/255;
  var a = mycolor2[3]/255;

  [r,g,b,a]

  Dan Ebberts replied 10 years, 2 months ago 2 Members · 1 Reply
• 1 Reply

• 

  Dan Ebberts

  March 1, 2016 at 5:43 pm

  You could do it by building a string and using eval() to evaluate it, but I think I’d just use nested arrays, like this:

  
myColors = [[81,45,10,255],
[38,184,82,255],
[255,157,150,255],
[19,23,148,255],
[119,241,225,255],
[255,59,212,255],
[44,134,120,255],
[255,89,10,255],
[235,213,8,255],
[236,39,34,255],
[228,212,136,255],
[186,38,138,255],
[255,142,144,255],
[48,205,187,255]];

  myNumber = Math.round(thisComp.layer("Null 3").effect("choosecolor")("Slider"));

  myColors[clamp(myNumber,0,myColors.length-1)]/255;


  Dan

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