Shield spam

When making a shield with a custom banner on the front when the mob spawns I get this message "The shield color for MythicItem BalderShield is configured incorrectly, must use a color from the Bukkit DyeColor ENUM."

Then my actual shield file looks like this

This happens to all the other shields I made which make for some pretty intense spamming.

BalderShield:
Id: 442
Display: '&7BalderShield'
Lore:
- ''
- '&7&oShield of the knights of...

Shield spam