Light conservation - I had this issue when I first started. Basically the material you have for the floor is a dark material, and isn’t bouncing enough light. Try a lighter material and play with the roughness values.
See how the room is being lit the same color as the floor? The indirect lighting is bouncing and the floor is absorbing the light
Thanks for the reply, I played around with the material, made it lighter, however I’m getting this wired colour shift (it was a lot worse, but as I moved the texture colour closer to white, it got better), is there a way to offset it?