ΔE 15.1, loose: different enough that you should pick on purpose. Iroko is noticeably darker, warmer than Webbing Khaki.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Iroko is noticeably darker, warmer than Webbing Khaki.
The same difference applies the other way round: Webbing Khaki is noticeably lighter, cooler.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Webbing Khaki on the colour wheel See Iroko on the colour wheel
All matches: Webbing Khaki equivalents · Iroko equivalents