At 15.12 the line on my graph is red. Not sure what i done wrong.
Hi HKB,
That's nothing to worry about. The colour is just for visual clarity.
Blender will use a different colour for sequential channel curves. Yours is red because that's what it uses as the default 1st colour.
The model that I started with already had a driver on it from the course where this was previously used. So that's why mine wasn't red.
I'm pretty sure I cleaned that from the starting model for you.
Hope that makes you unstuck.