Sorry, but I do not see how Tails in this image detects a Mod?! Undyed/dyed leather armor appears in frames gray or white. Undyed/dyed dropped leather armor also appears gray or white.
Linked issues
duplicates
Attachments
Comments

Ah! Sorry. I make a new one WITHOUT mods.
Unable to reproduce. Please force a crash by pressing F3 + C for 10 seconds while ingame and attach the crash report here.
The guy seems to have deleted the image, but I'm guessing by what Tails said that this is OptiFine.
EDIT: He deleted it and reuploaded a new photo. As Tails said, please generate a crash report and upload it here.

Cannot confirm.
Undyed leather armor is brown, dyed in it's dye colour.
See screenshot.

With an unmodified minecraft.jar all leather armor were gray. With a totally new .minecraft folder everything was normal. Strange.
I'm sorry, but since when do glass panes connect like that?