Since tracking your progress on unlocking the hidden appearance, and then on unlockign the different colour tints is not shown anywhere in game, I thought it might be useful if this information was shown in your artifact tooltip.
HiddenArtifactTracker
The addon began as a tooltip mod that showed your world quest/dungeon/pvp progress towards the different colours, but it now also includes tracking for the various steps in unlocking the appearance to begin with, at least for most specs - not every spec has something to tracker.