How to change the colour of the prices?
In Frequently Bought Together it is possible to configure the regular price, sale price and 'compare at' price colours from the app preferences page.
In the Visual preferences section, click on any of the three prices in the widget(regular, sale or 'compare at'), to display the price style options:
When you click on any of the prices, the colour picker will show up to allow you to select your prefered colour. You can also enter manually the colour value in hexadecimal format.