In STN technology, which uses LCD technology, the liquid crystals have a twist angle of 180 degrees to 270 degrees. Since the propagation speed of different light wavelengths in the liquid crystal is different, an STN cell can display colors. Depending on the design, the characters can be dark blue on a white background or green on a yellow background.
Compared to TN technology, STN technology is characterized by improved contrast values and a larger viewing angle. The disadvantages are undesirable color representations, which were compensated for in various ways in the later developed variants DSTN (D, Double), CSTN (C, Color), FSTN (F, Film) and TSTN (T, Triple).