hackaday.com/2015/02/07/how-green-screen-worked-before-computers/

www.newtek.com/blog/tips/best-green-screen-materials/

www.chromawall.com/blog//chroma-key-green

Chroma Key Green, the color of green screens is also known as Chroma Green and is valued at approximately 354C in the Pantone color matching system (PMS).

Chroma Green can be broken down in many different ways. Here is green screen green as other values useful for both physical and digital production:

Green Screen as RGB Color Value: 0, 177, 64
Green Screen as CMYK Color Value: 81, 0, 92, 0
Green Screen as Hex Color Value: #00b140
Green Screen as Websafe Color Value: #009933

Chroma Key Green is reasonably close to an 18% gray reflectance.

Illuminate your green screen with an uniform source with less than 2/3 EV variation.
The level of brightness at any given f-stop should be equivalent to a 90% white card under the same lighting.