Tuesday is the 60th anniversary of Jackie Robinson's first game in Pittsburgh.

Three generations of sports fans have clicked the turnstiles and the remotes since Major League Baseball's color barrier was broken.

So why are we still defining those involved in major sports by skin color?

Make no mistake. We are doing that, even if we're not always terribly aware we are.

Mike Tomlin isn't just the new Steelers coach. He's the first black head coach in franchise history and one of a few in major college and pro football.

It was the same with Lloyd McClendon, the first black manager of the Pirates, although the owners of the Pirates weren't largely responsible for a league rule about interviewing minority candidates as the Steelers were with the "Rooney rule" in the NFL.

The results of two studies released this month hold a large mirror before us, one with a deep reflection.

An ESPN/ABC News poll looked at Barry Bonds as he closes in on Hank Aaron's all-time home run record.

Questions about Bonds inevitably deal in shades of dislike, based on his personality and suspected use of steroids, but the survey also showed delineation by skin color.

While 52 percent of respondents don't want the San Francisco and former Pirates slugger to break Aaron's record of 755 homers and 37 percent do, there was a larger gap when broken down by race.

Seventy-four percent of black fans in the survey are rooting for Bonds, while only 28 percent of white fans are.

Further, 37 percent of black fans believe Bonds used steroids, compared with 76 percent of white fans. And 46 percent of black fans think Bonds has been treated unfairly -- due to the steroids issue, his race and his personality, in that order -- while 25 percent of white fans think Bonds has been treated unfairly, mostly because of steroids and not at all because of his race.

That's an incredible disparity. We'd like to think as sports fans we're color blind. Perhaps we're just blind to the truth.

The other study, outlined in an academic paper by Penn professor Justin Wolfers and Cornell graduate student Joseph Price, showed that in the NBA, white referees called more fouls against black players, and black referees called more fouls against white players. The latter was not as pronounced as the former.

Several prominent NBA players have scoffed at the idea of racial bias among referees, but the authors of the study seem to think it's more a matter of subtle feelings unearthed.

Wolfers called the results evidence of "implicit, unconscious biases," according to the Associated Press.

The NBA did its own study, looking at data from November 2004 to January 2007, just after the 13 years of box scores used in the academics' study, and proclaimed no racial bias.

There was no accounting for who called how many fouls on Yao Ming.

It's possible we're looking too hard for blatant or premeditated forms of racism in sports.

For all the talk of looking under the surface to see the value of people, it could be that a real look there is where we'll find the racism.

Consider John Amaechi, the former Penn State and NBA basketball player.

In a bigoted world, this guy has three strikes against him. He's foreign-born. He's black. He's gay, as he informed the world in a recent book.

Speaking at an annual convention of the Republican Party's largest gay organization earlier this month, Amaechi said he has been shocked at the response to his coming out -- shocked that he hasn't had to duck from waves of verbal darts.

"I underestimated America. I braced myself for the wrath of a nation under God," the English Amaechi said, according to the AP. "I imagined that it would be a fire storm, that it would be some insane number of letters demanding my deportation or my death.

"And, in fact, 95 percent of the correspondence I've had have been overwhelmingly supportive and positive. But I will say that the [other] 5 percent that I've had have been unbelievably, viscerally, frighteningly negative."

No word on whether that 5 percent included any white NBA referees.

Or on how the lack of the anticipated fire storm -- outside of Tim Hardaway's stupid, hate-filled monologue -- affected sales of Amaechi's book.

Perhaps, on the surface, we don't really care if athletes, coaches and management are black, white, Asian, gay, straight or Libertarian, as long as they come across as decent people, although it's telling that gay athletes aren't lining up to go public during their playing days.

In reality, we probably have a long way to go. For now, sports can still be defined as black, white and misread all over.