As much as i love my KSC75s, i've always hated the silver finish. They look a bit cheap and plasticy too.
So after much deliberation about paint markers, plastic dye, and spray paint, i decided to go for the latter. I was concerned about any paint getting inside into the mesh behind the speaker, but managed to overcome this by aiming the paint can at a very low angle and only spraying in short 1 sec bursts. There's a couple of mm depth to the holes speaker case, and a low angle was all that was needed to keep the paint out. To ensure i didnt get any runs i sprayed from a distance of around 30-40cm and in very short little bursts, moving round the headphones in a circular manner, again and again and again until all the silver plastic was covered.
The ear clips ended up with a smooth matte/satin finish, the speaker covers with a rough matte finish. The finish wont be to everybody's taste, but i'm very happy with the result and so far i've had no problems with the paint chipping or cracking. I imagine thats partly due to the amount of very thin layers i applied over a period of about 30 mins, then allowing them to cook in the hot sun for a good hour afterwards. Also the fact that i used some pretty tough Montana graffiti paint (colour: 'Shock Black').
I made sure to listen to the exact same track at the same volume before and after, and i could tell no difference in sound or volume. I'm very happy that they sound identical to before.
Here's the pics. Hope this helps someone else out who's been thinking about doing the same.
Take one normal pair of KSC75s
Pop off the clips by gently bending the clip away from the speaker case.
Lift the foam covers away from the edge and over the edge pins to remove
Mask up cables with tape
Mask up ear clips
Lay speakers face down on a dead flat surface (or paint will go underneath onto drivers)
Spray in short 1 sec bursts from a good distance and as low an angle as possible - around 30deg
Take your time, allow to dry between bursts of spraying
Slowly build up the layers of paint
Now for the clips, short 1 sec bursts again, let dry for 20 secs between each
Allow to bake in the sun for an hour or two (you could use a hairdryer i guess)
Here you can see the inner mesh is paint free
Gently pop clips back on and you're done
[ Disclaimer: I take no responsibility for you damaging your own headphones or getting paint in your eye using this guide ]