How can you remove black colour of AgCl from skin or hands?

By using chromatization method thus separation of colours of combined sources.

ANSWER

If you have black stains on your skin from playing with silver salts, you basically can't remove them. The black colour is caused by silver particles which get into pores and the surface layers of your skin. Silver is soluble in nitric acid but this is NOT an option for cleaning your hands. Luckily, skin is continually replaced and grows from layers the silver particles don't reach so, in a couple of weeks, the stains will start to fade and disappear in about two to three weeks depending on how dark the stains are.

Silver chloride is a notoriously insoluble white crystalline solid. It will decompose, like most silver salts, when exposed to light. This is the principle of the old black and white Photography.