increasing saturation

Hongfeng give me this values to increase the saturation to 1.6 , I just want to know how this value represent saturation 1.6? whats the formula?

/* Defaults for rgb2rgb, saturation=1.6*/
struct prev_rgb2rgb dm365_rgb2rgb_defaults = {
    .coef_rr = {1, 0x5a},   
    .coef_gr = {0xf, 0xb5},
    .coef_br = {0xf, 0xf2},
    .coef_rg = {0xf, 0xda},
    .coef_gg = {1, 0x34},   
    .coef_bg = {0xf, 0xf2},
    .coef_rb = {0xf, 0xda},
    .coef_gb = {0xf, 0xb5},
    .coef_bb = {1, 0x72},   
    .out_ofst_r = 0,
    .out_ofst_g = 0,
    .out_ofst_b = 0
};