How to create a custom colour palette in Tableau

To create a custom colour palette, open your Preferences file (Documents > My Tableau Repository > Preferences.tps)

It should look like this:

<?xml version='1.0'?>
<workbook>
</workbook>

All you need to do is add your colour scheme within <preferences> tags as shown below:

<?xml version='1.0'?>
<workbook>
<preferences>
<color-palette name="barbellchart" type="regular">
<color>#0585D6</color>
<color>#D65605</color> 
<color>#05D6BE</color> 
<color>#051DD6</color> 
<color>#D6BE05</color> 
<color>#D6051D</color> 
<color>#8AD604</color> 
<color>#D6048A</color>  
</color-palette>
</preferences>
</workbook>

Simply copy and paste the above between <workbook> and </workbook> and edit the name and the colours.

As mentioned in the video, if you want or need to choose some colours for your palette, there are some pointers this blog on using colour theory in data visualisation (in the last section on creating your own palette)