ΔE 17.1, loose: different enough that you should pick on purpose. Buff is a little darker, much more muted, cooler than Transparent Yellow Iron Oxide.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Buff is a little darker, much more muted, cooler than Transparent Yellow Iron Oxide.
The same difference applies the other way round: Transparent Yellow Iron Oxide is a little lighter, much more saturated, warmer.
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 Transparent Yellow Iron Oxide on the colour wheel See Buff on the colour wheel
All matches: Transparent Yellow Iron Oxide equivalents · Buff equivalents