any tips about setting up color arrays?
such as make a scene and/or global variable called Colors then have an array from 0 to 28. with each array being set to a different Tint in RBG format
My logic was to create no condition with an action for Colors 0 = 0-255-0, 1 = 0-225-225, 2 = 255-255-0 and so on.
the call array numbers to change object color randomly
If you simply want to change color randomly, you can use Random(255) without building the whole arrays 
If you do need to have an array filled with random colors, you can also do in a repeat x times event "append string ToString(Random(255)) + ";’ + ToString(Random(255)) + “;’ + ToString(Random(255)) to variable Colors”. Though like Gruk said, if you just need to set an object to a random color you can use that expression directly or use the random color extension.