Kevin,
'Rubicon' is a good red for being an older cultivar. I had reds pop up all over the place in spring, but by August they'd all faded except for a small handfull of ones from the 'Blue Balue' bee seed patch. Is 'Red Zinger' still red now? it's such a fleeting hue. I think there are two different kinds of red, those where the color rests atop the leaf (very similar to the good strong purples you've released) and ones where the color seems to radiate from deeper within the leaf and has a more translucent, glassy quality than the others which appear more as though someone has painted them with opaque acrylic. Both seem to be more prone to fading than purples with similar properties. I only made one cross for red in 2018, and only a couple more in 2019, I expect my best reds will come from this years crosses of which I've made many more than the previous years. 'Lady of Fire' is probably my favorite red and I've crossed that one with 'Cleveland Morgan', itself, a seasonal red seedling I raised from 'Ysolde' and a red cull I bought from you at the last clinic. I'm hoping it proves to be fertile, it had the reddest pink flowers I've ever seen, mostly because it's filaments were blood red and they cast a hue on the rest of the bloom, but as you can see in this photo from the German page there's actually some red in the center of the petals to, not to mention that the sepals are also red. Too bad my only rosette of the cultivar bloomed so I may not get another chance to work with it.

Now that's a beautiful semp bloom! I'd love to increase the red color on the petals, could you imagine such a thing as a pure red sempervivum flower! How spectacular that would be!
-Sol