Nail the exact color green in your design by using the code from any one of these systems for color identification.
|RGB||r: 0, g: 128, b: 0|
|HSL||h: 120°, s: 100%, l: 25%|
|HSV||h: 120°, s: 100%, v: 50%|
|CMYK||c: 100%, m: 0%, y: 100%, k: 50%|
If you're identifying color for pretty much anything digital, you're working in an RGB colorspace. If the project you're working on requires percentage representation, green is made of 0% red, 50% green, and 0% blue.
If you're identifying color for a print project, you're most likely using a CMYK colorspace—the percentages are 100% cyan, 0% magenta, 100% yellow, 50% black.