I tried using this. Yes, I am not good with scripts so what I tried may make you laugh so bare with me. I have gained a basic understanding of scripts but writing them causes problems.
vector color1;
vector color2;
vector color_blended = 0.5*( color1 + color2);
default
{
touch_start(integer num)
{
llSetColor(0.5*( color1 + color2);
}
}