What do the arrows mean?

[A_name]

When one activates the aero arrows in the debug menu, what does each color and direction of the arrow mean? For example, with a simple rocket right after launch I can see a red arrow protruding from the engine bell. Ok so that means red arrows show thrust, or the direction of a force acting on the rocket. But then when I start the gravity turn, red arrows show on the parts of the rocket where you'd expect drag. So red mean drag, then? Or maybe it does mean a force, but why do they point in the wrong direction (i.e. if they represent the force exerted by drag, I'd expect them to point in the opposite direction of movement, because drag slows you down, right?) All of this is confusing for me.

[Master Tao]

The lines show drag (red), wing lift (blue), and control surface (yellow) forces. They red ones should point roughly opposite the direction of movement. Are they not for you?

[A_name]

The lines show drag (red), wing lift (blue), and control surface (yellow) forces. They red ones should point roughly opposite the direction of movement. Are they not for you?

Yes, the red arrows usually point opposite the direction of movement. I think the confusion is because a red arrow always seems to be s coming from the middle of the engine bell, so I thought red had something to do with the engine's thrust. Still not sure why that happens though, since the engine should be shielded from drag by the rest of the rocket (at least immediately after liftoff when I'm flying straight up).