Blue racers have yellow bellies. You are totally clueless.
From the Blue Racer fact page:
http://www.oplin.lib.oh.us/snake/fact%20pages/racer_blue/racer_blue.html
Appearance
The Blue Racer is a long, fairly slender snake with back,
sides and belly colored plain black. Usually there is some
white color on the chin and the throat. The scales
are smooth, without keels, and the anal plate is divided.
This snake is similar in appearance and habit to its close
relative, the Black Racer. Interbreeding with the Black Racer
often occurs where their two ranges overlap. Resulting
offspring sometimes display characteristics of both parents,
or may look the same as one of the parents.
Tell them they are clueless.
I seriously doubt a blue racer would be that size nor near Houston TX.