Very much so. I-ICO yindawo yokugcina egcina ii-bitmaps ezisikwere ezininzi ngaxeshanye (16, 32, 48, 64, 128 ne-256 px) ukuze ii-Windows kunye nee-browsers zingakhetha ubungakanani obufunayo. That determines both the headroom available and whether the saving costs you anything in fidelity.
Yintoni impazamo eqhelekileyo xa uxinzelela ICO icons?