Replacing an ebike's cable disc brakes with hydraulic disc

Assuming you have eliminated contamination of pads or rotor as the cause you can consider a different calliper.

The bike spec on the website lists the brake spec as “Mechanical disc with alloy 3 finger levers.”

A drop in replacement might be an Avid BB7 or BB5 or Shimano BR-M375 calliper which might improve the strength of the brake without needing to figure out the mechanics of the cut-out switch at the lever.

However, mechanical disc callipers can also depend on good pull ratios at the lever to work well so you might need to figure out how to reproduce the switching mechanism with a new lever if a new calliper doesn’t give you everything you want.

The carrier metal of the pads is red because it looks cool. They are probably organic type pads for when it’s time to replace.