For example, save a file as .js containing:
const a = `b = ${b}`;
const b = `http://${host}/mydir/`;
'string';
// comment
In the case of a, the b = is black as if it were code. Only the ${b} is code, and b = is like a string.
With b, the // is interpreted as a comment (which it isn't) and the rest of the line is green.
Compare github's rendering of the above with FlashDevelop's.
This is on 5.1.0.3, win7x64sp1 (no updates available when I checked just now.)