I know that there was no official explanation on what provokes the plant to bloom with red spots/petals, however do you know from your experience if something helps?
Tetraspis will bloom with more red coloration when grown cool such as in the winter months. Summer, warmer months the plant will bloom with more white.
You also need to go back in time and pick the best parents for the cross.
Ha ha ha, good luck with that!
I am raising three seedling tetraspis plants, and I'm eagerly waiting (and hoping) to see blooms next year. I will be sure to keep them cool next fall and winter!