SEWING HELP: Improve Pedestrian Visibility As Wheelchair User

I have bike lights on my wheelchair, and they improve night visibility in fair weather. Unfortunately, from October through April, my outerwear covers up the lights. My cape* is wonderfully functional as wind protection and top layer in cold weather. BUT it’s black leather, and I want to be more visible, night and day.

ETA: Thanks to the extensive suggestions below, this problem was solved. Details at https://jesse-the-k.dreamwidth.org/319362.html

Challenges

• I know almost nothing about sewing, working with leather, or HIVIS materials
• Solution must withstand flexing even in very cold weather -10°F
• I throw the cape in the air to put it on, stressing seams in every direction — See pix 1
• Cape is not flat — see pix 2 and 3
• Cape is pieced together from 24 rectangles — see pix 4 — so solution needs to bridge many seams

( Reality check my ideas )