Hello!! First, thank you hehe <3 if you go to settings->profile, then you can change the colours pretty easily using colour codes (hex colours for example), but if you want to do alot more things like changing the shape of things or adding space here and there, then you'll have to add in some css in the Custom CSS section. If there's something you want to do but you're not sure what the css is for it, feel free to send another question <3