What does the colour picker actually do in the columns?

I am trying to work out where this colour applies as Ideally I am wanting a different colour for any items I mark as dependencies on my timeline.
Please advise if there are other ways to do this.

Hey @slash, thanks for writing to us about this! Colors in a timeline depend on the group color, so to change the color of an item you can change its group or change the groups color as below:

Would this help with the dependencies?

The color picker column is for working with specific colors and tracking down their respective color codes, if you work in design, for example. You are also able to select whether you’d like to work with the Hex Color Code or the RGB Color Code.