College and university endowments have recovered most of the losses they sustained during the recession, now that the economy has begun to grow. Yet as this year’s high school seniors begin to fill out applications and aid forms, a number of prestigious smaller colleges are straining to meet students’ financial needs. To bridge the gap, some colleges have begun revising their financial aid formulas, raising concerns about how campus diversity — both economic and racial — might be affected.

Wesleyan University in Connecticut recently decided to take a step back from its longstanding practice of admitting students without regard to their ability to pay, a process known as need-blind admissions. Grinnell College in Iowa is weighing whether it needs to move in the same direction.

Since the recession ended, a few colleges, including Williams College in Massachusetts and Dartmouth, have partly retreated from policies of providing aid only through grants, rather than requiring students to take out loans as part of their financial aid packages. Some other colleges continue to practice need-blind admissions, or have a policy of meeting the full financial need for most students, but have trimmed those practices around the edges, saying that they no longer apply to transfer students.

Administrators at highly selective colleges say they feel caught between financial reality and the fear that rising financial aid needs will result in a wealthier, whiter student population. “This is a conversation that’s probably going to occur almost every year for the next several years,” said Raynard S. Kington, president of Grinnell, “and I think that’s probably true at every other institution like ours, as well.”