Red and blue do not always make purple; the “red” you choose matters because some reds contain yellow, which dulls the mix instead of giving a clean purple.

What works best

  • Use a blue-leaning red, like magenta, permanent rose, or quinacridone magenta.
  • Avoid warm reds like cadmium red if you want a bright purple, because they often contain too much yellow bias.
  • Pair that red with a blue such as ultramarine to get a cleaner violet/purple.

Simple example

  • Good mix: quinacridone magenta + ultramarine blue.
  • Less vivid mix: cadmium red + many blues, which can turn muddy instead of purple.

Why this happens

Purple is strongest when the red has little to no yellow in it. Yellow and purple are complements, so any yellow in the red tends to mute the result.

Quick answer

If your question is “what red does not have purple in it,” the practical answer is: reds with yellow bias, especially cadmium reds, won’t mix into a clean purple very well.