Custom LED lighting for vehicle

Designing a custom light bar for my vehicle with 4W RGBW. To be used for off roading, volunteer fire, deputy sheriff, motorist assistance, and all around accent lighting. Never worked with any of this. The control board is by my logic going to need roughly 25 input pins and possibly 200 output. What board(s) do I need?

What on earth are you trying to do with 200 pins? Even if you have a board with that amount is very very impractical....

If you just want to drive LEDs, go for a LED driver chip (or multiple).

Got a link to the RGBW part?