Nicolas,
I understand the dilemma. But then I must ask for a format enhancment. Before crying out loud please read my argumentation. Why did I create my own "fancy" markers? Because there is no default way to recreate the "Textmarker-Experience" - or at least I couldn't find any. All default emphasis markers recreate what I would call the "Ballpoint-Experience". This puzzles me because marking text on a piece of paper is one of the most basic things. Do I have a point here or not?
I just opened my pen-drawer and took out the text-markers. I found (the typical) neon-yellow, neon-green, neon-pink and neon-blue. How about adding four markers using something like "org-emphasis-colours-alist" and let the users be able to define the colours?
Just one final remark: Tobias, the guy on stackexchange who helped me out here gave me a working solution, so I can live with that but currently I still think the "Textmarker-Experience" is missing in org-mode and should be inside it without any user defined functions.
With kind regards,
Jens Lange