Minecraft wiki entry for Player.dat_format, associated text:  display: Display properties.
 color: The color of the leather armor. The tooltip displays "Dyed" if advanced tooltips are disabled, otherwise it displays the hexadecimal color value. Color codes are the hex code of the color converted to a decimal number, or can be calculated from the Red, Green and Blue components using this formula:
Red<<16 + Green<<8 + Blue[2]
 Name: The JSON text component to use to display the item.
 Lore: List of strings to display as lore for the item.
A line of text for the lore of an item.
 HideFlags: Bit field determining which parts of the tooltip to hide on an item. 1 for "Enchantments", 2 for "AttributeModifiers", 4 for "Unbreakable", 8 for "CanDestroy", 16 for "CanPlaceOn", 32 for various other information (including potion effects, "StoredEnchantments", written book "generation" and "author", "Explosion", "Fireworks", and map tooltips), and 64 for "Dyed" on leather armors. For example, setting to 3 (1 + 2) would hide both "Enchantments" (1) and "AttributeModifiers" (2) tags, and setting to 127 would hide everything.