Indecomposable Soergel bimodules for Universal Coxeter groups

joint with Ben Elias ; with an appendix by Ben Webster,  Transactions of the American Mathematical Society 369 (2017), 3883-3910. We introduce the multicolored Temperley-Lieb 2-category. Using it, we find the explicit numbers for which "Soergel's conjecture in positive characteristic for Universal Coxeter systems" fail.