I always wondered why they chose a school bus as The Partridge Family's tour bus and how did they design it to be all strange colors for the bus? Because when my mom and I would see The Partridge Family in reruns I thought The Partridge Family's bus looked funny and how did they end up with the bus anyway? Did a school bus driver give it to them or did they end up with it as a gift?

I can't find anything on the reason they chose that design for the bus but the geometric shapes are based on a Dutch artist and maybe they thought it looked psychedelic for a singing group and would be better than school bus yellow.

I think they bought the bus at a used-car lot.

You can buy a school bus. There is one that they took the seats out of it, and put horses in the back and the people stay in the front when they go to horse shows.

I saw the debut episode of The Partridge Family a few minutes ago and it showed how The Partridge Family got their tour bus. Smittykins is correct that they went to a used car lot and bought a school bus. But The Partridge Family came up with the strange paint style themselves. And the very first concert that they used the bus to travel was in Las Vegas