Three phase well pump wire colors
There is no required NEC color coding for 3 phase pumps or motors with the exception of a high leg or wild leg be on B phase and marked orange, there are industry standards like Brown orange yellow for 480 but they can all be black. The only other requirement the phasing be front to back, top to bottom or right to left when talking about phase numbering in the NEC. I should add the ground is bare or insulated green.
To update for edit:  black red blue is the normal 3 phase color code For most companies but not all.
I do have a concern that you may be confusing 3 phase and 3 wire pumps 2 very different things. If you have an inverter you may have a 3 phase pump but if only standard voltage 240 3 wire is not the same.