ΔE 7.6, close: similar, with a visible difference side by side. Light Grey RLM63 is a little darker than Grau RLM 02.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Light Grey RLM63 is a little darker than Grau RLM 02.
The same difference applies the other way round: Grau RLM 02 is a little lighter.
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 Grau RLM 02 on the colour wheel See Light Grey RLM63 on the colour wheel
All matches: Grau RLM 02 equivalents · Light Grey RLM63 equivalents