Add a function to return different colors in a list as strings

[bradfordjohnson]

Think about arguments, and different themes + dark/light variants.

Might even want make functionality to print out plots with backgrounds as the color, labeled, and combine with patchwork to make "color swatches"

> function_x(2,theme="nord", light=FASE)

[1] "#4C566A" "#2E3440"