The best thing one can say about “Black or White,” Mike Binder’s attempt to grapple with the issue of race relations in the country today, is that it’s terribly earnest. The worst is that it’s earnestly terrible, a heartfelt but contrived and simplistic take on the subject that feels like it would be more at home as a “very special” cable TV movie.

Kevin Costner stars as Elliot Anderson, a well-to-do Los Angeles lawyer whose beloved wife Carol has just died in an auto accident. The couple were raising their biracial granddaughter Eloise (Jillian Estell) after their daughter had died in childbirth. The father was Reggie (Andre Holland), a drug addict who abandoned the girl and left Los Angeles. Elliot is devastated by his wife’s death, but struggles to carry on with Eloise, despite hitting the bottle awfully hard. That’s when Rowena (Octavia Spencer), the girl’s paternal grandmother, enters the picture. A hard-driving, hard-loving woman from South Central who’s built an impressive array of businesses on sheer grit and determination and supports a large extended family, she’s concerned about the lack of maternal influence—and cultural sensitivity to her background—in Eloise’s life, and enlists her brother Jeremiah (Anthony Mackie), a hot-shot lawyer, to file a custody suit against Elliot. Meanwhile Reggie, claiming to be clean, comes home and joins the case, though how serious he is about becoming a father remains in doubt—and his return sets off Elliot, who’s always blamed him for his daughter’s death and considers him nothing more than a junkie looking to extract some money in return for disappearing again.

The strength of “Black and White” lies in Binder’s attempt to depict the story in shades of gray. Both Elliot and Rowena are imperfect people—Elliot because he’s running on anger and Scotch, and Rowena because she’s blind to her son’s flaws and has a hair-trigger temper, as well as a tendency to bulldoze her way through any problem. The script also raises the question of just how post-racial American society is, and answers quite rightly that it isn’t, and is fooling itself if it believes—and acts—otherwise.

Unfortunately, even these positive points are dramatized without much subtlety or nuance. Costner and Spencer try hard—in her case too hard, in fact—but neither Elliot nor Rowena ultimately impresses as a fully rounded character. Costner comes closer merely because he has more screen time, but also because it appears that Binder, who of course is white himself, is more comfortable pointing out Elliot’s failings. By contrast he doesn’t offer much insight into Rowena’s character; she remains a sort of generalized earth-mother figure, far less developed than Lena Younger in Lorraine Hansberry’s “A Raisin in the Sun” was more than half a century ago, and Spencer attacks the part with a wide-eyed intensity that makes both the dramatic and the comic aspects of the woman come across as oversized and almost stereotypical. (Binder doesn’t even have the courage to depict South Central with much sense of reality: Rowena’s house—and that of her lesbian daughter across the street—feel like a Mayberry-flavored oasis.)

The rest of the cast don’t fare well under Binder’s heavy-handed approach either. Mackie, a fine actor, is, like Spencer, far too broad and aggressive, and Holland is similarly encouraged to play to the rafters. Bill Burr isn’t much better as Elliot’s friend and lawyer Rick, nor is Gillian Jacobs as his girlfriend Fay, though they get some (fairly weak) comic moments to play with. And young Estell is just too precious for words; she’s not far removed, in looks or precocity, from Quvenzhane Wallis in the new “Annie”—in fact, you half expect her to suddenly belt out “Tomorrow.” There’s some compensation, though, in the work of Paula Newsome, who has some great reaction shots as the family court judge, and Mpho Koaho, as Duvan, the ultra-prepared tutor Elliot hires as a tutor for Eloise (and an occasional driver for himself). They’re both sitcom-level characters, but the actors milk the parts for all they’re worth. Jennifer Ehle looks beautiful in the obligatory flashbacks as Elliot’s late wife.

“Black or White” is nicely made, with an attractive production design by Pipo Wintter and smooth cinematography by Russ T. Alsobrook, though Roger Nygard’s editing could be crisper (the two-hour film really indulges both Costner and Spencer overmuch) and Terence Blanchard’s score lays on both the sappiness and the comic boisterousness too thick.

In the end, though, it’s neither the behind-the-camera work nor the acting that sinks the film. It’s the wimpiness of Binder’s script, his unwillingness to treat the issues the film raises about race as seriously as they deserve. It’s no surprise that when things wind up, the outcome is nothing more than a long, innocuous cinematic take on Rodney King’s “Can’t we all just get along?”—a veritable group hug in which everybody does the right thing, and not in the Spike Lee sense. Somewhere Stanley Kramer might be looking down and nodding in approval—and that’s no compliment.