When I use my speedlight during an evening portrait shoot, there's a big difference in WB between the flash and the natural light. Is there a gel color that can counteract this?
I use both CTO and CTS. CTO is more on the reddish so I use it when the subject is on the pale side. If the person is more on the tanned side I use A CTS. This is just not for evening shots but event photography. Lately I find that I use the CTS more often.
I've had great success using (forgive the language) Bastard Amber gels in 1/4 to 1/2 cuts under warm sunlight.
Lay an oversized piece over the opening of a stofen or omnibounce and squish the face of your head into it for a nice snug fit with no light leak. Crumples the heck out of the gel, but who cares. Tape it on for full flash.