Hey there! Well, I don't usually start in grey cuz it's a mucky process working up the color afterwards. I would only start in grey if I don't have a clear idea for the color scheme or if I'm doing something that involves very neutral colors or if it's just a single light source. For more complex lighting that involves tons of ambience and subtleties I start with color from the very get go. I work in steps of lighting and use a photography language to help me render. The samus for example I knew I was gonna show local colors and not have anything crazy with the colors and ambient lighting so I started with a block in of local colors and decided on a strong directional light which made for very chiseled lighting on her body. Hope that helps?
Yeah that helps, I guess you could say I've been trying to find my "niche" on my process of drawing and i cant seem to find a great way of going about adding color. When I start in gray scale I seem to be able to make my process easier, but like you said adding color is a pain at that point. I'll just have to keep practicing with colors more. Glad to hear a response from you so soon btw, wasnt sure if you would see it.