Deep cut on hand been cleaning but drying with bright yellow crystal scab? Help!

Not enough info. Is the cut on the back or front? Can you move all the joints? Without further info, I can't tell. Go to an ED or UCC.
? Joint fluid. This needs to be seen. The yellowish fluid could be from the cut extending into a joint which is leaking out and causing the yellowish coloration. This should be evaluated by a hand surgeon if possible or at least seen in the ER. Get it checked out.