It's strange that they don't specify what gamut. I think it's possible that they mean 45% of the entire CIE gamut, which would be slightly larger than sRGB.

(It's an odd way of specifying a monitor though, usually manufacturers specify as a fraction of either Adobe RGB or Display P3.)

DCI-P3 is about 45% of CIE, so maybe that?

The product brief says 16.2M color depth, though, which would mean it's 6-bit + FRC which is bizarre to couple with an aim for DCI-P3, so perhaps not.

Quite an odd product!

I assume these are mostly all trade-ofs so you can power it on one of the Pi's USB-A ports without an additional PSU required.

You can also run much better panels off a Pi's USB-A port:

https://www.amazon.de/gp/product/B0CSJWPXBV/ 109,99€ for a 16" 2520x1680 60Hz 100% sRGB 8-bit panel. Power via USB-C, video via USB-C or mini HDMI.

45% NTSC is what I'd expect

I expected it to mean 45% NTSC.. panel gamuts are usually specified in marketing as either 45% NTSC, 100% sRGB, or some % of adobe rgb/display p3 for wide gamut

Not sure why they dropped the NTSC, maybe consumers have cottoned on to NTSC keyword = bad monitor