Suggestions?

I have the opportunity to create several webcasts for a colleague's wonderful site, Sensational Color.
The question is, what would people be interested in watching/learning about? For those of you unfamiliar with webcast, they are online presentations that can consist of various elements: video, power-point screens, tracking movements on the computer or web, etc.
The premise for these webcasts is to increase the educational content on color on her site.

So, what do you think I should do a webcast about, within the topic of color? The sky is the limit, but I want to hear what -you- would like to watch!