Lady Gaga Goes Ginger

Lady Gaga knows how to stick out -- at events, concerts and now ... on her film set, where her orange hair was hard to miss.

The usually blonde Gaga went carrot top on the "A Star Is Born" set this week. The Bradley Cooper-directed film was shooting Wednesday in L.A. ... and the ginger look is something new for the remake.

Gaga's role was previously played by Judy Garland and Barbra Streisand, neither of whom went red.

We looked ... Gaga's had orange hair before, so nothing new for her. Just a regular day at the office.