CiM Damson - purple as in Damson plums. This is a very red-purple when thin, and practically black when not.
Here - two self coloured beads. If they weren't black - you wouldn't know.
Here, on the left, over white, and over clear on the right. Here, you see the true colour of the glass. A reddish purple.
Just for fun - here are 3 that have fine-silver wire wrapped around them and melted in.