[media]
The item names are spelt with grey, while the minecraft: is all in gray for all items
MC-270993
Grey and Gray Spelling on Items
Resolved
Invalid
0
Hi hi AverageUser!
This is not a bug. The "minecraft:" tag you're referring to is the raw data tag for all Minecraft items. I assume you have your language on "United Kingdom," and that is why the spelling is inconsistent. The display name will change, but the raw data name won't (so as not to confuse the files.)
Glad I could help!