First of all, download “SwitchResX Control Panel” then start it. When it's done, click on “Export DCC” button. You will get a text file you'll have to open.

LCD panel reference is at the end of file, presented as

	Descriptor #2 is ASCII data:
			B133EW01 V0

Then you have to start you preferred search engine to search for the panel reference (first part, without version number, in this case “B133EW01”). With my MacBook, I can see it's a TN LCD panel, the brand is AUO, response time is 25 ms, contrast ratio is 400:1, number of colors is 262 000, etc.

About color numbers, a class action was started into United-States against Apple which pretends on its website that LCD panels can display millions of colors but it's not the truth.