ecotect , geco, and galapagos

hi forum ! So I've been playing with ecotect geco and galapagos... I've got it all working and feeding back and forth and set up a simple slider to control a facade element as a genetic variable so that when I change the slider the colors on the subdivided meshes that represent sun exposure update. and now I want to optimize the results towards a certain fitness so that the facade has not too much exposure but not too little. How can I measure the colors of the panels , which output rgb values, in a way that can be measured for fitness? I want to find geometric solutions that results in the range of the colors that has the greatest amount of mid range exposure... so my goal is to optimize the most orange and yellow with the least reds and blues...any ideas? I tried to isolate one color and find solutions that have the most appearance of that one color by dispatching the rgb values and measuring the length of the list that is true to match the color of the selected panel. but i'm looking more to measure against a range of colors... any ideas THANKS -ethan