Here is section 16 of the WPA's Equipment Spec. Does the new 9 ball not meet the criteria?
BALLS AND BALL RACK
All balls must be composed of cast phenolic resin plastic and measure 2 ¼ (+.005) inches [5.715cm (+ .127mm)] in diameter and weigh 5½ to 6 oz [156 to 170 gms]. Balls should be unpolished, and should also not be waxed. Balls should be cleaned with a towel or cloth
free of dirt and dust, and may also be washed with soap and water. Balls contaminated with any slippery substance – treated with a polishing or rubbing compound and/or waxed - must be cleansed and dewaxed with a clean cloth moistened with diluted alcohol before play.
A complete set of pool balls consists of one white cue ball and fifteen colour-coded, numbered object balls. The object balls are clearly and highly visibly numbered 1 through 15. Each object ball has its number printed twice, opposite each other, one of the two numbers upside down, black on a white round background.
The object balls numbered 1 through 8 have solid colors as follows:
1=yellow, 2=blue, 3=red, 4=purple, 5=orange, 6=green, 7=maroon and 8=black.
The object balls numbered 9 through 15 are white with a centered band of color as follows:
9=yellow, 10=blue, 11=red, 12=purple, 13=orange, 14=green and 15=maroon. The two printed numbers 6 and 9 are underscored.
