\documentclass{beamer}
% block
\setbeamercolor{block title}{fg=black,bg=green!50!black}
\setbeamercolor{block body}{fg=green!50!black,bg=green!50!black!30!white}
% alertblock
\setbeamercolor{block title alerted}{fg=black,bg=green!50!white}
\setbeamercolor{block body alerted}{fg=green,bg=green!30!white}
% exampleblock
\setbeamercolor{block title example}{fg=black,bg=lime!50!white}
\setbeamercolor{block body example}{fg=lime,bg=lime!30!white}
% theorem
\BeforeBeginEnvironment{theorem}{
\setbeamercolor{block title}{fg=black,bg=yellow!50!white}
\setbeamercolor{block body}{fg=yellow,bg=yellow!30!white}
}
\AfterEndEnvironment{theorem}{
\setbeamercolor{block title}{fg=blocktitlefgsave,bg=blocktitlebgsave}
\setbeamercolor{block body}{fg=blockbodyfgsave,bg=blockbodybgsave}
}
% corollary
\BeforeBeginEnvironment{corollary}{
\setbeamercolor{block title}{fg=black,bg=orange!50!white}
\setbeamercolor{block body}{fg=orange, bg=orange!30!white}
}
\AfterEndEnvironment{corollary}{
\setbeamercolor{block title}{fg=blocktitlefgsave,bg=blocktitlebgsave}
\setbeamercolor{block body}{fg=blockbodyfgsave,bg=blockbodybgsave}
}
% definition
\BeforeBeginEnvironment{definition}{
\setbeamercolor{block title}{fg=black,bg=red!50!white}
\setbeamercolor{block body}{fg=red, bg=red!30!white}
}
\AfterEndEnvironment{definition}{
\setbeamercolor{block title}{fg=blocktitlefgsave,bg=blocktitlebgsave}