Spelling of the word color/colour inside vec_constraint()

[gklarenberg]

We (@msanford17 and I) noticed that the argument for the color inside vec_constraint() specifically has to be spelled as colour - not color. This is different from customary ggplot() behavior, and ord_plot() also works with both spellings. It would be good if this was spelled out in the package documentation.

[david-barnett]

thanks for reporting this :)