Facebook, over the years, has changed its logo multiple times; it has stuck to the color that is still in use today. It is not a common practice to use this kind in web design, but Facebook has gotten away with it very well, and it appears that this color is here to stay.
Blue
PANTONE: PMS 7684 C
Hex Color: #1877f2;
RGB: (24,119,242)
CMYK: 90, 51, 0, 5
Facebook color has been verified by Meta.com, where you can find more information about its other brands, such as Instagram, WhatsApp, and Messenger.