What are the comparative and superlative forms of word purple?

The word "purple" doesn't have comparative or superlative forms because it's a color, not an adjective describing a quality that can be more or less intense.

You can, however, use words like:

* More purplish or less purplish to describe a shade of purple that is more or less intense.

* Deepest purple or lightest purple to describe different shades of purple.