Figure.makecpt: Make the 'reverse' parameter more Pythonic

[yvonnefroehlich]

Description of proposed changes

I feel it is fair to mention in the docstring that using the reverse parameter of Figure.makecpt also exchanges the background (B) and foreground (F) colors.

Upstream GMT documentation: https://docs.generic-mapping-tools.org/6.5/makecpt.html#i

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[seisman]

I feel it's a good time to make the reverse parameter more Pythonic. Instead of using reverse=True, reverse="c" or reverse="z", we may want to use reverse=True, reverse="colors" and reverse="zvalues" instead.

The long argument names colors and zvalues comes from the upstream PR https://github.com/GenericMappingTools/gmt/pull/8280/files (line 45).

[yvonnefroehlich]

I feel it's a good time to make the reverse parameter more Pythonic. Instead of using reverse=True, reverse="c" or reverse="z", we may want to use reverse=True, reverse="colors" and reverse="zvalues" instead.

The long argument names colors and zvalues comes from the upstream PR https://github.com/GenericMappingTools/gmt/pull/8280/files (line 45).

Sounds fair! Should this be done in this PR or in a separate follow-up PR?

[seisman]

I feel it's a good time to make the reverse parameter more Pythonic. Instead of using reverse=True, reverse="c" or reverse="z", we may want to use reverse=True, reverse="colors" and reverse="zvalues" instead.
The long argument names colors and zvalues comes from the upstream PR https://github.com/GenericMappingTools/gmt/pull/8280/files (line 45).

Sounds fair! Should this be done in this PR or in a separate follow-up PR?

Better to do it in this PR, since the docstring needs rewritten for the Pythonic reverse parameter.