My heater knob had faded to pink and although I'd bought a reproduction to replace it I thought I'd see if there was any way to bring life back to the original.
With little effort it is possible to restore the colour.
Firstly I rubbed down the pink areas a fine grade wet and dry and then with a small mop attachment and some polishing compound on my dremmel the colour started to return.
To be honest I didn't think it would work and stupidly I didn't take any before photos.
However I found this picture online and mine didn't look too dissimilar.
After amount 20 minutes it now looks like this.
Nice simple job if you want to polish your own knob.