Like trout feeding on midge pupas, many giant fish feed on small, fragile, easy-to-catch baitfish. Ninety-pound sailfish will eat 5-inch long Sardinas. One time we encountered three sails lounging on the surface. The guide tossed a Sardina at them. All three chased it and then several others. I threw a grey/white Baha Baitfish at the lead sailfish with a 10-weight rod. He took it without hesitation and stayed on for three jumps until the light leader came in contact with his raspy bill. Fifty pound dorados eat small baitfish and so will 30+ pound yellowtails. Big roosters, bonitos and lots of other fun critters eat a variety of small baitfish, including small mullets, flying fish and sardines. The Baja Baitfish series is tied on extra heavy duty, razor sharp Gamakatsu hooks so you can use 20-pound test tippet without fear. The flies are dressed rough looking on purpose. The extra-wide mylar dressed into these flies gives them an injured, scaled look. This extra material can be quickly trimmed of for a smoother, healthier look. Both presentations are valid in different circumstances.
Baitfish tend to bleach out when they are in shallow water. Mullets and sardinas turn grayish when over mud or sand bottoms. The gray/white color is a good start for shallow barren areas.
Many parts of the ocean bottom have vegetation such as algae. The baitfish try to blend in to keep safe from diving birds and foraging predator fish. The olive/white color is a good starting fly for many mid-depth areas.