poly is unidirectional for many years now, it is the only way to keep pushing the process technology further. not only it is unidirectional, it is also gridded. there is a very specific way to lay out poly in a regular fashion.
I think the colour issue you are referring to is simple metal coloring. it has been around for maybe 5 years or so? it has to do with process and how metals are deposited. it is a dual-tier process for the lower metals that are the hardest to print (say M3 and below). we say that you have M1C1 and M1C2, meaning metal 1 color 1 and metal 1 color 2. In innovus, it uses red and green contours to differentiate them. if you check the DRC rules, you will see things like M1C1-to-M1C1 distance and M1C2-to-M1C2 distance. they are not the same.