Tiffany is the more fleshed out of the two. Being a schoolteacher, she seems to share Slylock’s academic side. A common formula for puzzles is for Slylock to speak in her class.
They’re often seen with Max and Melody on double dates. This usually takes the form of the characters sitting somewhere cozy while Max recites word problems.
The syndicate colorists change their colors a lot. Bob Weber colors the Sunday strips, where he makes Tiffany orange with yellow hair. (Thanks for the info, Bob!)