So I have accumulated a disappointing amount of stains in my carpet (some of them even grease stains as I work with food) and I would like to know some sure fire ways to remove them with out ruining the carpet or moving the color around ect
Place carpet in dumpster.
Install new carpet.
Or something other than carpet where you have been prone to dropping food on it - sheet vinyl or some other easily cleaned surface.
A carpet cleaning machine may or may not work on any given stain, thus, this is the only sure-fire way.
I think you're out of luck in trying to get back to new & no future residue re-staining. Each stain will need it's own special treatment based on what the staining is from. Laundry Detergent will work wonders on 1-set of stains, Oxy Clean on another set, Vinegar & Baking Soda on another, Milk followed by Lemon Juice on another.
Your best bet is to get a Carpet Cleaning Company & relay what stain you remember being what since they have the inventory of cleaners for most everything. Then, invest in some ugly plastic Runners or much nicer Oriental Rug Runners to protect the traffic or spill zones.