Thanks for the links.
In the Customzier, you have set the Button Background color to be green (#9fb140) and the Color 2 option to be purple (#582354).
The button background takes the Color 2 setting only if you leave the Button Background empty.
The solution is to click the Button Background ‘Select color’ and then click ‘Clear’ and it will then default to Color 2, or just change the Button Background to your purple color.