Disclosed herein are dual cure coating compositions that include (a) a melamine-group containing polyethylenically unsaturated compound and (b) an acrylate-containing compound different from (a), wherein the acrylate-containing compound is present at a level sufficient to provide a cured coating layer having a glass transition temperature of 100° C. or below and a crosslink density of 20.0 mmoles/cc or below. Also disclosed are related multi-component composite coatings, coated substrates, and methods for coating a substrate.