Spell check colour names

We should spell check the names of colours that aren't found.

This might help users overcome issues like #272.

Python 3.10 has spell checking in a few cases including dict lookup, so does this happen already in 3.10? Colour names are looked up in pygame.colordict.

Start by tracing how colour names are looked up through pygame.colordict and compare the Python 3.10 dict-lookup behavior mentioned in the issue, using #272 as the motivating failure case. Done means missing colour names receive the intended spell-check behavior and the lookup behavior is covered by the relevant project tests.

Written by the indexing model from the issue text.