I kept three bottles because of the colors they match up for my models.
To use them, just treat them exactly the same as you would Vallejo, they are the same formula, manufactured by the same company.
The color matches are different, though, which makes them more useful if you build a certain genre of aircraft or tanks over another.
Rule #1, a rule that you can never break,,,,,,do NOT use Alcohol with Italeri paints, this is not so serious with a paint brush, you just clean everything up and start over,,,,,,buy, you will not like what Alchy+Italeri/Vallejo will do to an airbrush.
the three "matches" I kept are (matched to FS 595A, not B or C)
#4721 "33538 Flat Insignia Yellow",,,,,,matched FS 23655 Lemon Yellow/Light Yellow, just a bit on the light side
#4714 "31136 Flat Insignia Red",,,,,matched FS 21105 Red perfectly
#4682 "12197 International Orange",,,,,matched FS 22190 and BSC-537, because it didn't have the Red needed for International Orange
note, I kept these three not because they matched the labels, but, because they matched other colors I needed
Rex