The fact is, if you look at the last ten years of nominations for Best Actor and Actress, you see many white people coming up year after year.
Leo Di, Jeff Bridges, Daniel Day Lewis, Eddie Redmayne, Brad Cooper, Clooney, Brad Pitt, Christian Bale, Colin Firth, and Joaquin have all received at least 2 nominations, with four of them winning the Oscar.
In the same decade, Terrence Howard, Forest Whitaker, Will Smith, Morgan Freeman, and Chiwetel Ejiofor were the only black guys to get nominated, and each was only nominated once (Forest was also the only guy who won an Oscar during this time period).
For best actress, three or more noms have been given to Meryl Streep, Cate Blanchett, Kate Winslet, Jennifer Lawrence, and 2 noms to Reese, Sandra Bullock, Judi Dench, Michele Williams, with seven of these women winning the prizee since 2006.
In that same timeframe, only Gabourey Sidibe, Viola Davis, and Quvenzhané Wallis were nominated, once, and none of them won.