You will run into problems with the green leds on outside of boat if not anchored if the law catches you in non anchored state. But they are also great to have if you have nav light failures keeps you from getting hit sometimes.
Green lights outside the boat can be an issue (whether anchored or not) depending on their placement. The display of green or red lights visible outside the vessel is restricted to use assigned by the USCG regulations (which Texas adopts). For green light, this means from straight ahead to a point 112.5 degrees to the starboard (that's the right side for those who don't know). A green light visible from any other angle is a violation of USCG rules. This isn't arbitrary - there's truly a method to the madness, but many recreational boaters don't take the time to think about WHY these rules exist and why they're like they are.
You can tell a lot about a boat displaying proper lighting - such as general direction of travel relative to your own vessel, and whether it's underway or at anchor. When other boaters start randomly displaying green or red lights, the information that could have been gleaned from looking at other vessels' lighting is lost.
Buried within the USCG regulations is a rule dictating that no vessel shall display a light of a color or in a manner so as to confuse that light with the mandated navigation lighting.
Example: the Rigid Minn Kota TM bracket light with a white light at the bow. Guess what? That's a docking light, actually only allowed when in the process of docking the boat. Some anglers have found that running on plane across the lake with that light on isn't cool per TPWD.