Earlier quoted context omitted.
First off, it's art. You need to stop thinking like a programmer and think more like an artist. That means thinking about colors and lighting, tones and hues and highlights and shadows. If you're unfamiliar with these things, that's fine, you can find plenty of training material and courses online. It takes time, because it's a skill that requires training and practice and self-discovery. Second, lighting is a carefu…
Just a nit: the lighting outside is not a single directional source, unless you're in the Moon. There is sun, which is slightly yellowish (or orange to red at sunset), and there is sky light which is obviously bluish. Sun is directional, sky light is not. Sun is a light source far away, but sky is a light source all around the scene. The rest, well, can be done with a lot of bouncing, refraction, diffusion subsurface…
The sun light is white during the day, otherwise, anything white would appear yellow.