excel - Formula to add the sum of a range of cells with same "description" only -

i go more detail question title here:

so lets in range l3:l10 have list of descriptions (i.e. red, blue, green, etc.). if enter running list of random colors cells, lets say, f3:f600, quantity of widgets in color cell right (g3:g:600), formula can put in m3:m10 sums number of entries respective color.

i have range on sheet2!a3:a10 initial inventory of each color stored. want able keep running inventory of colors have , how many have of them. , if got new initial inventory because of shipment, have change sheet2!a3:a10 data , rest.

i had attempted following formula in cell m3 , dragged down m10 did not work.

=sheet2!a$3:a$10-if(l$3:l$10=f$3:f$600,sum(g$3:g$600),0) 

i have tried folllowing , dragged down through m10:

=sheet2!a3-if(l3=f$3:f$600,sum(g$3:g$600),0) 

neither of work. both seem work @ first because when there nothing in f & g columns shows initial inventory listed on sheet2! supposed to, once input data cells is supposed calculate from, nothing changes.

i believe you're looking for:

=sumif($f$3:$f$600,$l3,$g$3:$g$600)