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, blush pink is made of 100% red, 51% green, and 55% blue.
If you're identifying color for a print project, you're most likely using a CMYK colorspace—the percentages are 0% cyan, 49% magenta, 45% yellow, 0% black.