Whether this is in the form of money, success, health, etc. We all want to be happy, it's our main aim. And whilst this word has a different meaning to everyone and is obtained through different things or actions, there are certain colours that can induce that emotion and can make you feel a bit happier.
This colour is meant to give you more energy and stimulate liveliness, this obviously has an impact in your overall mood making you a bit happier. It's also been suggested that looking at that colour can increase your heart rate and blood pressure, so maybe don't paint your bedroom walk red if you wan to have a peaceful night!
Blue is usually the colour of serenity, it can make you more relaxed and calm so helping with stress and anxiety. Unlike red, blue induces sleep so it would be a great colour for your bedroom! I really like the colour baby blue and often find myself buying room decor that is this colour... now I have an excuse to buy even more, amirite?
Pink is one of my favourite colours, I've noticed I always gravitate towards pink coloured things (apart from clothes, in which case black and white is all I wear) and having pink details in my room makes me happier and improves my mood. Apparently there's this thing called "the pink effect": pink, specially a shade known as Pepto Bismol, can make you feel more calm.
Who doesn't love a clean bright white room, it gives a very zen vibe. It also makes the room seem less cluttered and more open, making it look bigger. I personally always tend to go for lighter colours, specially in my room, as I think it makes me feel more relaxed than if I have bright green walls for example.