The colouration is extremely strange I was working on my model when blue 'sharp' lines appeared. I didn't understand these at first and closed out and reopened to see if that would fix the problem. I then did some research and found out how to get rid of the lines, but now everything looks very strange. Help?
Edit: It looks fine in Sculpt Mode. I've tried adding and removing the sharp edges and nothing has changed.

Thanks in advance.
Blue sharp lines didn't just appear-- you did something to make them appear.  But, they were probably always there.  Probably, because you imported this mesh using a function that marked edges containing custom, per-face normals as sharp edges.
The solution?  If you were happy with your normals before you cleared sharp edges, but not after?  Roll back to just before you cleared sharp edges.  Or else, remark those edges as sharp, if you remember which edges they were.