Whenever there is representation of dark ages and early middle ages people from Scandinavia, they are always drawn as wearing bright blue, yellow, red and orange tunics and robes. How accurate were these depictions and if so, how were these clothes created, and did these bright colours hold any symbolic meaning beyond the fashionable?
There's more to be said about specifically Scandinavian access to dyes, but you may be interested in this answer by /u/madderandiron: