We have here a very usual word.
First, think of Rule 7: כ is the conjunction that means like, as.
And for גון surely it appears in your dictionary under its absolute form גָּוֶן, a masculine noun that means colour. Look at ptr N-t113.A.1.
Here we've the singular construct: גּוֹן, (the) colour of.
Look at ptr N-t004.A.3.
We thus get like (the) colour of.