Principal English Translation: 

blue ashes? blue clay? blue amaranth?

Orthographic Variants: 
Alonso de Molina: 

texouauhtli. bledos o cenizos azules.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 112v. col. 1. Thanks to Joe Campbell for providing the transcription.

Attestations from sources in English: 

auh ce pitzaoac om jcxi yiopochcopa, qujpotonj in jxocpal, yoan qujtexooaoan in jmetz vmexti. yoan vmexti in jacol = And on his one thin foot, his left, he had the sole pasted with feathers, and he had stained both of his thighs with blue mineral earth, and both upper arms (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 3 -- The Origin of the Gods, Part IV, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1978), 4.