Easing in Checkbox Control Effects

Try this, it's based on code Dan Ebberts helped me with:

fadetime = 0.5;
dur = 2;
p = effect("Checkbox Control")("Checkbox");
grey = 'cccccc';
red = 'ff0000';
val = hexToRgb(grey);
if(p.numKeys > 0){
    n = p.nearestKey(time).index;
    if(p.key(n).time > time) {
	n--;
    }
	if (p == 1) {
		endCol = red;
		startCol = grey;
	} else {
		endCol = grey;
		startCol = red;
	}

    if(n > 0){
        t = p.key(n).time;
        val = linear(time, t, t+fadetime, hexToRgb(startCol), hexToRgb(endCol));
    } 
}
val

Not a matter of simply using a built-in function or canned expression. You still have to calculate the time backwards from your keyframe. For a single(!) keyframe on your layer this could be as trivial as

key(1).time-0.5

and then you pipe it into a linear() expression

linear(time,key(1).time-0.5,key(1).time,0,1)

which needs to be repeated for all three color channels. Things will however get infinitely more complicated if you need to toggle this multiple times on teh same layer. You would need to run it in a loop, check which keys are on and which ones are off and you may also need to have extra checks so the differnt fades don't overlap and get in teh way of each other. All that being the case, it would probably make more sense to keyframe the color directly or e.g. the opacity of a Fill effect or similar.

Mylenium