This forum is where you discuss issues relating to molting hermit crabs, including pre- and post-molting issues. If you are having a molting emergency please post in the Emergency Forum.
I honestly can't say. I have never noticed the change in leg colors. I usually notice that my crabs start digging and pigging out more before going down for molts.
On freshly molted crabs the joints tend be yellow or orange, and they fade to match the rest of the body color over time, usually a few weeks or a month afterwards.
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