SC Official wroteNFHS there is nothing illegal so long as the color restrictions are satisfied.
3-5-3: Arm sleeves, knee sleeves, lower leg sleeves, compression
shorts and tights are permissible:
a. Anything worn on the arm and/or leg is a sleeve, except a knee
brace, and shall meet the color restrictions.
b. The sleeves/tights, compression shorts shall be black, white, beige
or the predominant color of the jersey and the same color
sleeves/tights shall be worn by teammates.
c. All sleeves/tights, compression shorts shall be the same solid color
and must be the same color as any headband or wristband worn.
d. Meet the logo requirements in 3-6.