There have been many colour groups on PonyIsland over the years, their popularity has risen and falled over time. Some were connected to the Azuyan Roleplays, some with various Associations, and others purely related to the interests of various player groups. This is an attempt to provide a brief guide to the ones used on the Colour Matcher and provide links to more details about each. It is not a definitive guide, more of a starting point.
This resource was compiled by Jadzhia.
The word 'pure' when used on PI in relation to colours only applies to the eight colours shown in the chart below and specific shades of grey. This quotation originally came from the PI Bulletin board, and applies to PI's definition of 'pure':
Sometimes you will come across the term GAP colours. These are the even intervals between the Pure Colours, such as 9900FF, 663300, etc; These colours were important in Azuyan roleplaying, particularly the challenge of building a legion of 36 ponies. The idea was to choose one element (e.g. Storm) and one particular slot (e.g. Hair) and then breed all 36 colour hexes.
You may wonder why some of the colours are listed as being in more than one group. This is because the Legion colours overlap. If you study the colour charts you will be able to see this more clearly. If your pony has a hex that could belong in two different legions, you can choose which Legion you would rather your pony joins , but he/she cannot be in both. For example, if your pony has the hex FF0033 (255|000|033) then he/she can join either a Twilight or a Flame Legion but not both, as that shade falls into both groups.
Lord KORR (one of PI's site mascots) has his own special colours, the KORR Exclusives. Some of these shades overlap with other groups, such as #A0A0A0 which is also a shade of pure grey in the Sugar colours. Your pony does not have to be a follower of KORR to use these colours. For instance, KORR's Rubies can just be called Ruby on ponies with no allegiance.