Color ramp resources other than Color Brewer?

I strongly recommend Colorpicker for data: http://tristen.ca/hcl-picker/#/hlc/6/1/15534C/E2E062

It's designed with color ramps in mind and allows for lots of flexibility while maintaining a clearly understandable ramp.

Here's a couple places to start...

https://twitter.com/foundpalettes

https://designschool.canva.com/blog/100-color-combinations/

Good question. ColorBrewer is definitely my first go-to, but it's getting old seeing the exact same palettes in every map ever created in the post-colorbrewer world.

I have been playing around with cubehelix color palettes lately with census data for bivariate choropleths. I just sample the palettes with illustrator, then tweak them (usually with Illustrator color guides) for optimum perception between classes.

This cubehelix palette worked really well with two skewed-right distributions: