TI definitively cannot brag about how they innovated with a color screen calculator, because Casio already achieved it 16 years before. In fact, the CFX-9900G was the first ever graphing calculator to feature a color screen and
Totoyo on Planète-Casio found a video of an old commercial of it (in French), advertising the color screen:
CFX-9900G TV commercial from 1995The
CFX-9900G is the ancestor of the
CFX-9850G series, featuring 3 colors (which can be changed via contrast settings), but the difference is that it has a 96x64 screen instead of 128x64. It has 24 KB of RAM.
Unfortunately, around 2003, Casio discontinued all their color screen calculator models, replacing them with the black and white FX-9750G, which is a shame, considering the potential an Algebra FX or 9860G would have gotten if the color screen was manipulated in assembly or C language. Although colors can't be changed extremely fast, the way contrast works on those calculators could have allowed color palettes in games like on old gaming consoles such as the NES and Sega Master System.
And using the z80 ASM technique of creating 3-level grayscale, maybe more than 3 pixel colors could have been used at once?
Sadly, running ASM on those calculator models seemed to require flashing the ROM chip, making it out of reach for the average calculator user. Fortunately, however, 16 years later Casio decided to revive color calculators with the Casio Prizm, which features an even better color screen and much more hacking potential. TI then followed with the TI-Nspire CX series, although tools to run ASM games on it are in constant danger of getting blocked by newer OSes.