I've seen nothing about lights being Coast Guard approved, but PFDs must be.
http://tpwd.texas.gov/fishboat/boat/safety/vessel_requirements/There seems to be conflicting language about red/green nav lights. The following quotes are all from the same page shown in the link.
"All vessels including motorboats, sailboats, canoes, kayaks, punts, rowboats, rubber rafts, or other vessels when not at dock must have and exhibit at least one bright light, lantern or flashlight visible all around the horizon from sunset to sunrise in all weather and during restricted visibility."
One white light required.
"All other manually driven vessels may exhibit sidelights and a sternlight, or shall exhibit at least one bright light, lantern, or flashlight from sunset to sunrise when not at dock."
Red/green nav lights optional.
"Regulations state that canoes, kayaks, and all other manually driven vessels shall exhibit sidelights and a sternlight, and shall exhibit at least one bright light, lantern, or flashlight from sunset to sunrise when not at dock."
Red/green nav lights required.