If you head to 'Account':

 

Then down to 'Settings':

 

You'll arrive on the default tab for that section, which is 'Customisation' 

 

One of the options here is giving your page a custom Theme Colour.

We’ve pre-selected some great looking colour palettes for you and we’re always adding more.  

 

Simply select the colour from the available palette that best represents your page, then leave the rest to us!