Red walls?

Is it true that if you paint your walls red it makes your room feel hotter?

I don't think so...I think it's black because black can make anything hotter. (like you can't wear black on a hot day, cause it makes you hotter)

it is definitely a possibility, but a colour like red can really bring character in your room...

I did something similar in mine, I got the wall behind head rest of my bed, a gave it ocker colour ( between dark yellow and light orange as the the window is opposite side, so even with the curtains closed the room was always bright and active.
keep the neutrals to vibrant colours 3:1 or 4:1 ratio your room will definitely gain personality but too much of it will make it difficult to sleep in.

In fact, there's a lot of research to indicate that colours do affect how we feel.

A lot of people do FEEL warmer in a red room, just as they may feel cooler in a blue one (not a good idea for a bedroom in a cold country). Yellow helps to perk up many people - I once painted the inside of my kitchen cupboards BRIGHT glossy yellow, to get me awake when I opened them to make my morning cup of coffee.

And hospitals have long since realised that pale green helps many people to relax.

Unfortunately, schools and municipal offices still seem to go heavy on the sickly brown-yellow paint...

I don't know