Don't worry, they did those too
https://www.hattons.co.uk/1056112/hattons_originals_h4_6fb_1702_6_wheel_full_brake_72_in_cie_light_green/stockdetail
there's also a few 6-wheel 2nds, a 2nd brake and composite lav in light green
EDIT: Just realised you probably meant a 4-pack - yes, I agree: they did it for most of the other liveries (including the dark green) so it is a little strange they didn't do it here too. Perhaps as @Westcorkrailway says, its because they don't anticipate as much demand?