Some cape textures have white backgrounds instead of transparent backgrounds

The Bug:

Some cape textures have white backgrounds instead of transparent backgrounds.

Affected Capes:

Affected:

• dB Cape
• MineCon 2012 Cape
• Mojang (Classic) Cape
• Mojang Cape
• Realms Mapmaker Cape
• Scrolls Cape
• Translator Cape
• Translator (Chinese)
• Translator (Japanese)

Unknown:

• Valentine Cape
• Birthday Cape

Steps to Reproduce:

1. Go to https://sessionserver.mojang.com/session/minecraft/profile/<UUID> and replace "<UUID>" with the UUID of a player that has the said affected cape currently equipped.
2. Copy the value of "value", go to https://www.base64decode.org/, paste the value, and decode it.
3. Copy the "CAPE" URL value and open the link in a new tab.
4. Save the image and open it.
5. Take note as to whether or not some cape textures have white backgrounds instead of transparent backgrounds.

Observed Behavior:

Some capes have white backgrounds and some have transparent backgrounds.

Expected Behavior:

All capes would have transparent backgrounds.