I´ve used two whitewall paints myself and read of several more.
The usual problem of all of them, white turning yellow because of the soot/coomb/carbon black (whatever?) coming from the tyre rubber might not be an issue here, maybe the red turns a bit brown-ish.
BUT one paint (from the US) even peeled off like sunburnt skin, although I followed the sellers instructions.
Maybe the german
ravus trim ring system is an option for you, as they are available in red or red-black, too?
Available up to 15".
Of course, you can´t decide how far away the red stripe should be from the rims edge. On the other hand, if you need a new set of tyres or you don´t like it any longer, you simply remove it without any tools.
These rings are fixed by either a beauty ring or a large hub cap.
They are not clamped between tyre and rim like other rings, so they do not destroy your tyre subtly, either.
I added a link to the ravus homepage up there. Unfortunatley it´s all in german and, don´t ask me why, they simply do not show pics of those red rings either. That´s why I took a pic of one of their suppliers.
A set of four rings in 15" costs 78 euros.* They might fit with your existing beauty rings, but I don´t know that for sure of course.
In case you want to try them, one trick I used myself: I bought a set of full white rings, but wanted white+black ones.
Many people apply vinyl stripes in bright colors to the outer edge of their rims.
I applied black stripes to the full-white rings to turn them into that black+white version.
That way you can decide how wide the white or in your case the red stripe should be.
*edit: 78 euros (or 131 euros with four stainless beauty rings, plus postage) may sound expensive, but that paint from the US will not be much cheaper when you add the shipping costs.
And if you don´t like the look at all, you can still sell on those rings - other than that paint.
In case I sound like a salesman: I have nothing to do with ravus.
