FYI, an allele is defined as "One of the alternative versions of a gene at a given location (locus) along a chromosome." (http://ghr.nlm.nih.gov/glossary=allele) In other words, alleles are compatible genes.
IMO, as fire, piebald, and lesser are not alleles, calling fire a piebald type gene is no more helpful than calling it a leucistic type gene.