‘It’s the wild colour scheme that freaks me out,’ said Zaphod, whose love affair with the ship had lasted almost three minutes into the flight. 'Every time you try and operate these weird black controls that are labeled in black on a black background, a little black light lights up in black to let you know you’ve done it.’

Zaphod Beeblebrox, The Restaurant At The End Of The Universe

Just use a perfectly efficient solar panel

They are all black by default but give off color when powered.