Ummmmmmmmmmmm - this is a trick question I know!
Like ah, you have a model choice of:
1. Colour
2. Black and white
All colour units basically have the same red/blue/green that gives you all shades therein and black & white gives you, ummmmmmm black & white?? Mono I think they call it ......................
................. or did you mean the brand name such as Hummingbird, Furuno, Lowrance etc?