Maybe you were thinking of "Platinum " phenotype as a dominant lavender colour (no lav in them), which is one dose of Bl blue, one dose of I^D dun.
Coffee laced and Custard are not hobby names someone has just made up recently. They are old Australian Pit Game and OEG variety names, been around for many decades, maybe over a century. The name Custard Pile has been around for even longer in OEG. Remember that these old game strains have been around for centuries, predate poultry exhibition standards, and that the American OEG Standards differ dramatically to the British OEG Standards in regards to what is accepted in colour/ patterns. The Coffee Laced do not have the I^D dun gene in them. The heterozygotes have a bronzing effect over black. Probably need to be homozygous for the dark coffee eumelanin. There is no pale khaki phenotype with the lacing, although the main tail feathers may have some greyish tan colour in the custard gingers (but this might be due to Bl which also segregates).
What are hobby names are the I^D dun based breed varieties . After Doc Hollander et al. formally named the mutation I^D dun (extracted from a pit game rooster), they dispersed I^D birds to hobbyists /backyard breeders to keep the mutation going. Unfortunately multiple times these breeders ignored the official name dun, how it ended up that I^D dun Polish were named Chocolate, USA I^D OEGB were named Fawn. Which is a shame, considering the name Dun is a traditional British OEG name (although interchanged with Bl birds as well).
