Colour-Card/background questions

I’m new to Toon Boom, and I was wondering if it’s somehow possible to make the background or Colour-Card layer gradually brighten in color as the animation progresses on? Any answers would be appreciated.

Using a Colour Card, keyframe the Alpha-Channel, either in the Parameters in the Timeline,
Or, in the Node-View…

Otherwise, keyframe Transparency,

Or, experiment with Colour Scale:
http://www.nolanscott.co.nz/colour_scale.mov
(no sound, it’s all very easy and straight-forward)

Thank you! I’lll try this.