Stained glass doesn't have colors on maps

^{Update by [Mojang] Mega_Spud (Jay Wells):}
Summary:
Stained glass does not show up on maps, as it does in the Java edition.

Steps to Reproduce:

1. Fill an area with stained glass
2. Open a locator map

Observed Results:
The stained glass is transparent, just the same as normal glass.

Expected Results:
The colours of the stained glass should show on the map.

Screenshots/Videos attached: Yes

Notes:

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Original Description:

Stained glass doesn't have colors on maps, I was using a resource pack when I took the screenshot but it happens without it as well