ΔE 19.4, loose: different enough that you should pick on purpose. Russ. AF Light Blue is a little lighter, more saturated, cooler than Trollblood Highlight.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Russ. AF Light Blue is a little lighter, more saturated, cooler than Trollblood Highlight.
The same difference applies the other way round: Trollblood Highlight is a little darker, more muted, 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 Trollblood Highlight on the colour wheel See Russ. AF Light Blue on the colour wheel
All matches: Trollblood Highlight equivalents · Russ. AF Light Blue equivalents