ΔE 13.8, fair: the same colour family, but not a straight swap. Light Yellow is a little darker, much more muted than Sunny Yellow.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Light Yellow is a little darker, much more muted than Sunny Yellow.
The same difference applies the other way round: Sunny Yellow is a little lighter, much more saturated.
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 Sunny Yellow on the colour wheel See Light Yellow on the colour wheel
All matches: Sunny Yellow equivalents · Light Yellow equivalents