It may depend on the rule set he is playing under.
MLB (unless they have changed it for this season) has:
3.07 Pitcher's Glove
(a) The pitcher's glove may not, exclusive of piping, be white, gray, nor, in the judgment of an umpire, distracting in any manner. No fielder, regardless of position, may use a fielding glove that falls within a PANTONE® color set lighter than the current 14-series.
You can take a look at PANTONE 14-series colors here: https://www.hyatts.com/pantone...tches-14-xxxx-2.3304
It has some green on there. I think the glove you pictured is darker than those, but you know - judgement call.
Realistically I can't see an umpire whipping out a Pantone chart on the field.
Distracting in any manner... again - judgement call.
NFHS has:
ART. 6
....The glove/mitt worn by the pitcher that includes the colors white and/or gray shall be removed from the game upon discovery by either team and/or umpire.
So, high school rules specify white or grey without making a distinction on piping/lettering. I've never seen that be an issue, but it is technically a rule.
The green glove though - no high school rule against it.
Technically.