There is a lottery of Full HD displays on both the X1C5 and X1Y2. You either get a superior AUO (AU Optronics) one with 85-90% sRGB / 60% adobeRGB or a BOE (Beijing Optoelectronics) one with 60-65% sRGB and 35-40% adobeRGB. Brightness and contrast ratio is also distinctly superior on the AUO panel, whereas the BOE just barely meets the minimum that is 300 nits / 1300:1. In case of the X1Y2, another FHD supplier is LG that currently produces to an equal standard as AUO, unlike some few known cases in the past.
Other than these two, All other FHD displays are same as BOE at color saturation, except with less brightness at around 260 nits and less contrast at around 1000:1. An effort from Lenovo to upgrade (just little enough not to lose buyers) since the last 3 years (220 nits, 700-800:1, PWM). But clearly they're still very much unsuitable for any color related or outdoor field work/play, which is quite unfortunate.
Sony and Toshiba did a good job using good quality screens on their business laptops, as do Microsoft and Apple on consumer devices today. Toshiba Portege for instance packs a FHD display nicely made: https://www.notebookcheck.net/Toshiba-Portege-X20W-7600U-512-GB-Convertible-Review.207592.0.html