final color selection; color decision
Used in contexts like auto paint shops or manufacturing where a final color is chosen from options. Not a general term for choosing colors.
色決めの段階で、お客様にサンプルを見ていただきます。
At the color decision stage, we have the customer look at samples.
Compound of 色 (color) and 決め (deciding, from 決める). The exact origin is uncertain, but it likely arose in industrial or commercial settings where a final color must be settled.