This monitor stands out for its color accuracy - it has a built-in color calibrator and was factory calibrated as well - see attached screenshot. This monitor retailed for about $3000 when first released in 2019.
I'm not a colorist by any means but I understand that the color performance of this monitor is a cut above your average 4K monitor. Digging around online seems that HP used a Panasonic IPS panel.
Here's a review:
https://www.techradar.com/reviews/hp-dreamcolor-z31x-studio-display
And here's a link to the B&H page with marketing copy and tech specs:
https://www.bhphotovideo.com/c/product/1388947-REG/hp_z4y82a4_aba_31_1_dreamcolor_z31x_studio.html
Note that the monitor does take about 10 seconds to awake from sleep and that HP recommends the monitor be turned on for at least 30 minutes before serious use to allow for the colors to stabilize.