Can a color sensor detect more than one color at once WHILE distinguishing them?
For example: Say I wanted a program to activate only if both red and violet are detected at the same time. Is that possible? How could I do that?
Think of a colour sensor as a single pixel camera. If you held up a red and blue object to this sensor it would detect both of those as a combined signal, purple. If you want to differentiate with more detail, you need more resolution.
There are tons of cheap camera modules available which you can use for various tasks. OpenCV makes extracting useful data much less of a hassle.