Denver Broncos fans are excited about Peyton Manning's debut this Sunday, but one Colorado school district won't let it's students wear the familiar number 18 of the former Colts legend.

Listen to Ray Steele's extended report:

The school system in Weld County, Colorado bans students from wearing clothing that depicts certain numbers, numbers school officials say are associated with gang activity. The number 18 is one of them, which means kids who are Broncos fans can't wear Peyton Manning jerseys to school leading up to Manning's debut with the team.

"Peyton Manning's been my favorite football player for a long time," said third-grader Konnor Vanatta to Fox 31 TV in Denver after he was sent home from school this week for wearing a Manning jersey.   "They told me I couldn't wear 18 anymore because it's a gang number, and I had to take it off."

Konnor's mother also doesn't understand the rule.  "I'm pretty upset about it, pretty upset that the schools have come down to this. I think they need to start paying attention more to the education the children are getting rather than what they're wearing," said Pam Vanatta to the television station.

Weld County Schools spokesman Roger Fiedler says the numbers 13, 14, 18, 31, 41 and 81 are barred from being displayed on clothing in all schools because law enforcement has told the school district the numerals are associated with a variety of gangs.  "We do try to really take a strong stance on any sort of clothing or display of gang affiliated material or signage," Weld told the TV station.

Fiedler says the school district loves the Broncos as much as anyone, but he says they want to spread a consistent message that gang activity will not be tolerated.

(Hat tip to Fox 31, KDVR-TV in Denver)

Follow me on Twitter @WIBC_RaySteele