What Is the Opposite Yellow?

The complement of any primary color can be made by combining the two other primary colors. For example, to achieve the complement of yellow (a primary color) one could combine red and blue. The result would be purple, which appears directly across from yellow on the color wheel.

Is yellow the opposite of purple?

The opposite of purple is yellow on the color wheel. Purple is also considered yellow's complimentary color.

Is blue the opposite of yellow?

By definition they're not really complementary but opposite. So in general, when people talk about complementary, they still refer to the traditional model: purple and yellow, orange and blue, red and green. By the way, that "blue" from the RGB wheel is still very close to be a purple in CMYK; but in RGB, it's a blue.