Yes Chat: your correct, There are treble buttons to change for C or B griff. My comment was to relate to the question as I understood ,"Extra buttons for cosmetic appearance".
For example - All black -All white - or a design of your choice.
And just a note -- all "V" accordion button models (with the exception of the new 8xb) have buttons of Roland design. The new FR-8xb has treble button tops that are the standard industry type and can be found by many US, UK, Italian and German suppliers in many different designs and colors.
For example ---http://frment.com/keyboard/accordion-buttons/