Proper vertical display of the Texas flag according to the Texas Flag Code: Section 3100.002 (which describes the flag) and Sec. 3100.059 (which describes the proper vertical display of the flag), explicitly: 


(b) If the state flag is displayed vertically: 
     (1) the blue stripe should be above the white and red stripes; and 
     (2) the white stripe should be, from the perspective of an observer, to the left of the red stripe.
Own work - This file was derived from: Flag of Texas.svg:
Tuckerresearch
File:Flag_of_Texas.svg
Derivative work: Fry1989