I feel your pain. I've had a similar experience.

What I would suggest is to try and find a CMYK variation of the blue and green you want that has the best possible 'pop' ( or brightness). Don't include much ( or all ) black in the mix, it will dull things. If you have too level of the other three, it will grey things out. Just think, what colors "pop" best in print? 100% Cyan + nothing, 100% Magent + nothing, 100% Yellow + nothing. So mix your CMYK blend accordingly. Also, educate the client about the difference between CMYK, RGB, and Pantone. And think about how often the brand colors will live in print versus screen. In print, think about whether it will be worth it to print PMS for branding materials like cards and letterhead, etc... or to print CMYK. I mean worth it in terms of time / money. Anyway, good luck!

Q: Have you heard about the new pirate font?

A: It's all Arrrrrrrrrrsss!

The article cited by the author of this post concludes with this:

"Word shape is no longer a viable model of word recognition. The bulk of scientific evidence says that we recognize a word’s component letters, then use that visual information to recognize a word. "

Which would appear to contradict the original author's statement of "(;tldr is that you read ‘shapes’ not individual letters)."

I do not see how this paper supports his claim against hollow icons.