A silver image and dye image are provided in a photothermographic element comprising a support bearing, in reactive association, (A) a silver compound capable of forming a silver image, and (B) a dye-forming combination comprising (a) a cobalt (III) amine complex capable of releasing ammonia or an amine at processing temperature in the presence of silver and (b) an aromatic 1,2-dialdehyde capable of forming a dye upon reaction with an amine or ammonia. Improvements are provided in such an element by a cyclic imide melt former-silver solvent which is capable of promoting dye formation at processing temperature. A silver image and dye image are formed in such an exposed photothermographic element upon thermal processing. The photothermographic element optionally can comprise a dye image receiver layer.