There's never gonna be a skin/theme that makes everyone happy but of all the available themes, the only one which fits all the conditions requested by the developers is Phoenity.
It's an original creation and isn't based on any specific OS or browser.
Icons are clean enough to work with all backgrounds(including no background). It also holds up well in 256 color mode unlike most of the others.
It isn't the default and AFAIK has never been the default of any other browser, yet is one of the most familiar and popular themes in all alternative browsers.
Its icons are easy to understand and don't require a text description beneath them.
It blends well with all Windows versions including XP, unlike the current IE5 skin which clashes terribly with XP and makes KM look old & outdated.
Getting permission from the author shouldn't be a problem since he provided the K-Meleon version on the themes page and he encourages others to distribute Phoenity with different backgrounds etc...
I don't think you can say that any of the other available themes meet ALL the above criteria, so any opposition to it would simply be based on personal taste. But it's hard to fathom that there'd be more opposition to Phoenity than to the current relic.
Wow, I never thought that my artwork is that good. Thanks for the compliments, jsnj.
Yes, Phoenity is an original creation. It is designed with practicality, simplicity and beauty in mind. I read a lot of toolbar icon design guidelines and mostly inspired by Matthew Thomas's guideline. The icons I've created for K-meleon are so-called clean, because the anti-aliasing pixels have been removed so that they can blend in any background. Phoenity has never been the default for any browsers, but it has been included in other software such as Maxthon, XNview and GGSearch.
I've tried hard to make my icons as understandable as possible. Sometimes, I test them by decreasing the color depth, step by step, until containing only two colours, black and white. I also make sure that my icons blend well not only for Windows, but also for Mac and Linux environments. I use some of my own concepts making the icons unique in such a way that is different than other millions of icons on the web.
Best of all, I'm sharing my artwork with everyone. Non-commercial and free of charge.