I'm glad you enjoyed reading the article. I completely agree on not really having a "right" way to blend gradients. For that reason I almost ended up omitting the gradient example from the article because doing it "correctly" in linear space does not always yield the most pleasant looking results. Generating perceptually fine looking gradients is another huge (and very interesting!) topic in itself, so maybe I'll discuss that in another post in the future.

Until then, have a look at this online gradient generator tools that can use five different algorithms (there's some explanation provided as well for each method):

http://davidjohnstone.net/pages/lch-lab-colour-gradient-pick...

I also recommend reading the superb 'Subtleties of Color' NASA article series on the matter:

http://earthobservatory.nasa.gov/blogs/elegantfigures/2013/0...

PS: I'm slightly confused about your comment on the black to white gradient though. Are you saying the gradient on Figure 1 looks more even to you than on Figure 2? In that case, I think your monitor is miscalibrated, so try gamma-calibrating it first then have another look. Your opinion might change :)