Here we go.
enum ItemQualities
{
ITEM_QUALITY_POOR = 0, //GREY
ITEM_QUALITY_NORMAL = 1, //WHITE
ITEM_QUALITY_UNCOMMON = 2, //GREEN
ITEM_QUALITY_RARE = 3, //BLUE
ITEM_QUALITY_EPIC = 4, //PURPLE
ITEM_QUALITY_LEGENDARY = 5, //ORANGE
ITEM_QUALITY_ARTIFACT = 6, //LIGHT YELLOW
ITEM_QUALITY_HEIRLOOM = 7
They are defined in SharedDefines.h
And maybe check item.cpp , item.h
But I'm not sure how the DB will apply new entries.
Also there was a way to edit item name colors without adding new qualities.