What I expected to happen was...:
When I broke the stained glass the lighting color would disappear.

What actually happened was...:
The color was still black and I had to go near it to make the color disappear.

Steps to Reproduce:
1. make a beacon then let it glow up
2. put a black stained glass [That's what I used] above, 4 blocks higher, etc.
3. Break the stained glass.
4. You will see a black [or whatever color you used] light after you broke the glass.
5. Step in/near it to make the color disappear.