Define a consistent visual theme for graphical outputs from the package

[aridf]

As we implement more ggplot and mapping tools in the package, it would be nice to decide on a consistent theme for the plots. There are a lot of built-in ggplot themes. I am partial to theme_bw() myself, but we could also make our own. For colors, I'm wondering if Latino Decisions has a branding color palette we could work from

[hikari-murayama]

Just thought I'd post here what fellows discussed the following for standardizing our visual themes:

• Bold axis labels
• Use theme_bw()
• Prioritize b&w printability
• In the case of using colors, use color palettes that are color blind friendly

Not sure if others have details to add!