Add optional color palettes - #107

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Hi, can you pull the latest changes from trunk, so that the color palette can be tested easier with the templates?

The preview of the palette in the option only shows five colors, so the palettes look very similar.
If you move the accent colors before primary, the accent colors will show in the option.

@carolinan Hello, i have merged trunk into the PR and re-ordered the colours :)

I saw your question, but lets merge this so that it can be tested and used, and iterate when or if needed.
Thank you.