They are posters, so the colors will definitely look different in print than on screen. I’m guessing these are spot colors from the Pantone catalog. The nomina

They are posters, so the colors will definitely look different in print than on screen. I’m guessing these are spot colors from the Pantone catalog. The nominal sRGB value is often quite different from what the actual pigment looks like in different kinds of lighting. The lighting of the space is something to consider particularly for poster color design, as posters typically need to look striking from a distance in rooms with uneven lighting.