I WONDER - How Did Vikings Dye Their Clothes?

The Vikings used vegetable dyes and plants to color their clothing. By boiling their clothes in these plants, the colors would transfer, resulting in various hues such as yellow, red, purple, blue, brown, and gold. Some dyes were also imported by wealthy Vikings.

Can you name a specific color that the Vikings used for dyeing?

What were some sources of dye for the Vikings besides local plants?