Please refer to the image above. These objects that I made, and any other items that I change the background colour of, suddenly is doing this where it looks like it is either transparent, or is blending colour, but as you can see in the effects menu next to it, the blending mode is Normal and the opacity is 100%. This is true for png pictures that have a transparent background - if I add a colour to them, they do this. This wasn't happening before and I haven't done anything to them just created some objects and gave them a colour.
I discovered this problem when I changed some text to outlines and gave them colours afterwards, then I discovered it does this to everything I add colour to now.