ΔE 13.0, fair: the same colour family, but not a straight swap. Light Mustard Khaki is noticeably darker, warmer than Putrid Green.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Light Mustard Khaki is noticeably darker, warmer than Putrid Green.
The same difference applies the other way round: Putrid Green 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 Putrid Green on the colour wheel See Light Mustard Khaki on the colour wheel
All matches: Putrid Green equivalents · Light Mustard Khaki equivalents