Looks like the longer toes has a bit of retained shed on it. You might want to give him a bath once a day in lukewarm water (like baby bath water) until it comes off. You may have to use a soft bristle tooth brush to gently brush it . this might take some time but it could save the toe. When toes come off, they don't grow back.
SLAVE TO A KIND BUT, DEMANDING MASTER "PEACHES"
The wonderful world of bearded dragons is a land of mystery, enchantment, cuddles and, worry! A magical realm where things always seem to change in an instant and, the moment you think you have it all figured out, the rules change! You think you own your dragon?, Ha Ha....guess again..... Like it or not, you are now a slave, lol!