(as) red as a beet

Blushing or flushed, especially from embarrassment. Primarily heard in US. I was red as a beet when the teacher made me speak in front of the whole class. Oh, Mike definitely likes you—he turns as red as a beet every time you're around! Are you sure you don't need help carrying that? Your face has gone as red as a beet!

red as a beet

Flushed from embarrassment, sunburn, physical effort, or some other cause. Although many of the similes involving red are very flattering, notably lips as red as a cherry or cheeks as red as an apple, being red as a beet is not: for example, “After six hours over a hot stove, Jane was red as a beet.” Neither is red as a lobster, as in “A day at the beach left Bill as red as a lobster.”