The state of Michigan has come to its senses. A few months ago its department of social services removed a 21/2-year-old boy from the custody of a couple who had cared for him for more than a year and then petitioned to adopt him. They would have been caring and competent parents by any standard, but the state found a problem: the parents' skin was a different color from that of the child. No state has a law that actually prohibits interracial adoptions, but many have policies to that effect. These prejudicial practices, incidentally, were given impetus by a 1972 policy declaration of the National Association of Black Social Workers strongly opposing interracial adoptions.

The Michigan couple sued and last week the state agreed to settle the case. The state pledged to cease making race a primary factor in considering the placement of children and to give equal billing to such factors as physical and emotional needs, a goal of permanence and attachment to the foster family. That sounds perfectly sensible, and one wonders how states have rationalized any other practice.

Last year, columnist Carl Rowan wrote of a similar case in Maryland where two white special education teachers, eminently qualified as parents, were temporarily thwarted in their attempt to adopt a mildly retarded black boy of 3 who suffers from cerebral palsy and hearing and vision problems. At first the state wanted to return him to the temporary arrangements that are the fate of many handicapped children. Mr. Rowan protested the "abominable notion that race must be the dominant factor in deciding who can deliver loving care and protection to a child. I hear some black social workers talk about a black child's right to be brought up in a family of the same racial background, and I think it is 1954 and I am hearing a white Jackson, Miss., editor tell me that every child has the right to be educated among children, and by teachers, of the same racial background."

It would be wonderful if no child ever had to be adopted or placed in foster care. It would be nice if -- given the need for such measures -- each child could be matched with adoptive parents who resembled him physically and in every other way. But there are not enough adopting parents of every race to take care of all the children who need them. Fortunately, many adults want to care for children no matter what the color of their skin or the severity of their handicap.

Last week, the Senate Labor and Education Committee adopted an amendment offered by Sen. Howard Metzenbaum to prohibit states receiving certain funds from discriminating in adoption. Failure to enact such a provision would be an admission that racial prejudices outweigh the desperate needs of children.