IIRC, BMM has the 'official' method which is dice color coded so that those who are color blind will be able to tell the difference.
The reason is simple, to help the game move faster . . . so I can look at your mech with a white die displaying a 2 and know while planning my fires (or even movement) without asking what your mech did- in that case, walk for a +2 TH. This lets me calculate what modifiers it will be for you to hit me, and what my modifiers will be to hit you. This is also the standardized format at official events with the color coding so that you do not have to ask what the table 'colors' are . . .
. . . with that said, I do not know if infantry have their own color in BMM but for mechs & vehicles it is white/walk, black/run, and red/jump. I think, I know jump is not green because that what we used before following BMM. Our table uses a different color for infantry and since we use sprint/overdrive TacOps rule, a color for that movement mode. Our group also has little markers for 'Standing Still' and 'Immobile' since those are different modifiers.
We also try to put dice directly behind a mini's rear facing on the base, so if you torso twist the 'rear' is still clearly marked for others.