// inject color j+1 in color j, how much depending on how much weapon_stats is higher than level j
float factor;
factor = (weapon_stats - acc_lev[j]) / (acc_lev[j+1] - acc_lev[j]);
// inject color j+1 in color j, how much depending on how much weapon_stats is higher than level j
float factor;
factor = (weapon_stats - acc_lev[j]) / (acc_lev[j+1] - acc_lev[j]);