This mutation is characterised by a diffuse or absent coloration in the body feathers of a bird. The wing markings exhibit a dark (black) coloration at the upper part, gradually fading to a light grey towards the wingtips. The standard for the Texas Clearbody (aka TCB) variety dictates that the body feathers should be devoid of colour, resulting in a predominantly yellow or white appearance, depending on the budgie's base colour (either just white in blue/white based budgies, or just yellow in yellow/green based budgies). However, in some instances, the Texas Clearbody may display up to a 50% dilution of colour in the body feathers. In such cases, the coloration is more pronounced towards the vent and rump feathers, being the darkest on the back. Best quality Texas Clearbody is just black and white (black and yellow) with very little or no other colour.
There is a similar variety of Clearbody mutation, called Easley Clearbody (ECB). It resembles Texas Clearbody, however his black markings of the wing feathers, as well as flight feathers and mask spots are even blacker (TCB has grey flight feathers, ECB has jet black flight feathers)
ECB: Look at her flight feathers (the longest feathers of the wings). They're solid black
TCB: Look at this one's flight feathers. They're grey (plus there is much more white in the wings)