Bug report

Bug summary

The current colormap options reflect American English spellings for 2/3 of the colormaps with a flavor of gray. An alias to the gray definitions using the standard UK spelling of grey would be helpful.

Colormaps that would need aliases for the UK spelling include:
gray, gray_r, nist_gray, nist_gray_r

Colormaps that use the UK spelling and would want an American English alias are:
Greys, Greys_r