ΔE 15.6, loose: different enough that you should pick on purpose. Royal Blue is a little darker, much more saturated, warmer than Uniform Blue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Royal Blue is a little darker, much more saturated, warmer than Uniform Blue.
The same difference applies the other way round: Uniform Blue is a little lighter, much more muted, 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 Uniform Blue on the colour wheel See Royal Blue on the colour wheel
All matches: Uniform Blue equivalents · Royal Blue equivalents