Colours and Metal

It's called synesthesia...

The only album I think of as a color (that I can remember at this moment) is Tales From the Thousand Lakes by Amorphis, and that color is of course blue (hence the cover)
 
Dol Guldur - a bright, grand orange/yellow
Thousand Swords - sky blue
Changes - fiery red
Slumber of Sullen Eyes - beige
Arghoslent - earthly greeny/beige
The Work Which Transforms God - dark greyish blue

etc
 
This topic reminds me of some poetry of Rimbault who put colours on the different letters ...
imo, Gontyna Kry are gold, Warloghe are grey/dark blue, Arghoslent are red, Absu are blue, etc ...