From the Greenlining Institute:
Over the past several years, increasing national attention has been focused on the need for foundations to become more aware of the opportunities presented by our increasingly diverse nation. In this brief, we present figures on the diversity of the nation’s 46 largest foundations. Over 90% of all foundations and 20% of the largest foundations have little or no paid staff (Foundation Center, 2007‐2), which effectively delegates the ultimate decision on which proposals should receive funding to the handful of trustees that make up the board. Since foundations are most often not held accountable to any entity outside themselves for their funding decisions, most trustees will decide which causes or organizations to fund based on their own notions of which causes are worthy of funding, as well as their personal and professional networks. Having a culturally competent board of informed givers is therefore essential to increasing a foundation’s impact on communities of color.
The entire report is available here. You'll notice a number of significant education donors are given the dubious distinction of zero persons of color on their board of directors, including the Bill and Melinda Gates Foundation, the Walton Family Foundation, the Michael and Susan Dell Foundation, and the Annenberg Foundation.