Nothing to worry about here, IMHO.
The blue and brown specks on the urates are intestinal waste. The blue color is caused by bile salts from the liver. Blue or green coloration generally occurs when a snake has not been fed in a month or two. Much of the intestinal waste is made up of hair from the prey. When the snake has not been fed for a while and the gut has emptied out, it takes a while for waste to build up in the cloaca. As hair from fuzzy rats is minimal, it takes longer than with older rats with more fur. Be patient; the poop will return to normal within a couple of months.