White is not " white" , it is usualy greyed for coverage. If you pick white for ceilings and a beige tone for the walls it will not look right, you need a beige tone white. Regular white "greyed white " goes with blues and greys.
Mixing in wall color balances it out, usualy a quart or so. But it depends on your color scheme, and starting with " ceiling white" which is greyed is a mistake. Use a premix " beige " white. I just had 2 ceilings Faux finished dark and it looks great , the ceilings are now worth looking at. Your painter is color blind unfortunatly, and not much of a decorator in a decorating business. Use your instinct, not your painters.
Benjamin Moore has the best colors and people there can usualy direct you. Sherwin Williams is a second or third. You say you are using Earth
- beige tones, so definatly do not go standard " Greyed" ceiling white. Same for Trim color White is greyed, based to blues and grey. Pick your colors well, once they are up , they are up.