Yes - I had mine powder coated.
I'm pretty useless with a toolkit - it's easy!
View attachment 32441
Dismantle the filler cap - you can only powder the metal bits obviously.
Instructions in the workshop manual. Take care when removing the screws in the photo below nothing drops in the tank!
Once you have the assembly removed from the tank, you can separate the black plastic shown in the cap from the metal parts by just undoing the screws. Simple!
View attachment 32449
agree 100%.
The black looks good with the yellow.