Before all the continents had split apart killifish or an very close ancestors of theirs were swimming around in ponds ans streams in the Gowanda Land supercontinents. When they split apart these fish evolved under different circumstances - Pupfish evolved in the Us deserts while their remote sister Aphanius evolved in the Mediterranean. Roloffia evolved in West Africa while it's remote sister Cyonadichthys, a subgenus of large Rivulus can be found in the part of South America that separated (Sonnenberg 2013) from West Africa - numerous other examples about; here are only a few.

fra-goby riv-rol
sjo-tail str-mah

Similarities in disparate spcies of killifish

Although it's well understood African and South American killifish split off about 250 million years ago rates of evolution are not the same everywhere. If they evolved very slowly, which some do (some don't) then we mught expect to fine related fish that still share an ancestral color pattern. These are all examples of this.