When all colors of light are mixed together, the result is white light. When all pigments (such as paint) are mixed together, the result is typically a shade of gray or black due to absorption of different wavelengths of light.
So, the answer depends on the context:
- For light: white
- For pigments: gray/black
Given the options, if you are referring to pigments, the result is gray/black; if it's about light, the answer is white.
If the context is not specified, I would suggest black or gray based on the common understanding of mixing physical colors (pigments).