There is a lot of science behind the colour palettes that are built into Tableau. If you want to learn more about it, I suggest you watch this video on The Science of Color and Visual Design Principles.
You can also read more about the topic of colour palettes in Tableau in this article and learn about Best Practices for Using Color in Data Visualizations directly from Tableau.
If you simply want to create some fun, engaging and visually appealing colour palettes that suit the content of your data story or fit with an image you’re including in your dashboard, then check out the tools below. These websites let you create colour palettes with a few clicks and you can take the hex codes and add them to your preferences file.
lets you create a custom palette from a photo which you upload to the page
drag the markers across the wheel to create a 5-hue colour scheme
Pick a colour, mix and match the others, reorder, drag, drop and save
similar to Adobe’s colour wheel
I created this spreadsheet to speed up the process of creating the right xml script for the Tableau preferences file.
Simply add your hex coded and an optional description for each colour, as well as a name for the palette, copy the script that is generated and paste into your preferences file. Easy!