Down here it seems that almost all companies are set up to offer pricing ONLY on including weed control, fert and disease control. Each company may vary a little by not including some weeds while others do treat them in their program.
I am not aware of any company around here that offers just straight fertilization. I am sure some smaller operations may agree to offer a color only option but I am not aware of it. With the pest and disease issues lawns down here can face most homeowners seem to want it all included.
10% of your customers are 90% of the problem.
You may think the grass is GREENER on the other side, but if you take the time to water your own grass it would be just as GREEN.