Hi, everyone. I'm new, my question is...

I bought a 2002 Ford Ranger Edge XLT 4X2 Supercab, when I bought, it comes with an horrible tires, bad condition, the size was 31X10.50R15, I think this size is wrong. All the internet and the fuel cap says 235/75R15, I put in it the extra tire under the bed, the truck needs tires NOW, I don't know wchich tires put it on. I think the 235/75R15 do the truck a little ugly.
Friends who have this truck, which tires use?

Do you guys think I got used to seeing it (truck) with those tires (31X10.50R15) and now that I put 235 / 75R15 look thinner? Will it be my perspective?

Thanks a lot-




Picture: This is my truck but mine is white.