Why do not you try it? In my case - I am working on colored ~25 kD proteins - the static FTIR spectrum looks quite uninformative: main water band,  methyl and methylene bands of lipids, two Amides,  plus a protonated carboxyl from the lipids .... However, when I took the second derivative (from an ATR-measured spectrum), I was able to see the bands of the chromophore inside protein, and, of course, the water bending band at 1638 cm-1, which was a shoulder in the FTIR spectrum,  was now nicely separated from the Amide I vibration @ 1659 cm-1.