High solids curable film-forming compositions and coating kits are provided, comprising: (a) a polyisocyanate curing agent; and (b) a film-forming component comprising at least one of (i) a secondary-hydroxyl functional (meth)acrylic polyol having pendant ester functional groups and a weight average molecular weight of 4000 to 8000; and (ii) a reactive constituent comprising: (1) a polymeric polyol comprising a polyester polyol and/or an addition polymer that is different from (i); and (2) an organic medium comprising a hydrophobic and/or sterically hindered reactive diluent having hydroxyl functional groups. Alternatively, the film-forming component (b) comprises the secondary-hydroxyl functional (meth)acrylic polyol (i) and optionally at least one of (1) and (2) above. The (meth)acrylic polyol comprises 20 to 35 percent by weight residues of an epoxy functional ethylenically unsaturated monomer. Methods of improving appearance of an effect pigment-containing coating layer on a substrate are also provided.