If I remember correctly Ninja medics use red shields.
Copy/paste from Wiki.
The most focused attacks cause the harshest reprisal; Laser, Electricity and Stab cause only 25% damage. Piercing, Fire and Concussive are next in succession, dealing 50% damage. As the attacks grow 'softer' so reaction is less coherent and the energy loss is greater. Cutting, Plasma, Chem, Bio and Daze dish out full damage. EMP is the bane of these shields, draining their energy fast with 250% damage multiplier. Mind and Warp attacks are too sneaky to be noticed and they go right through.