One place where she's said to be a femme fatale in Lancer Spy is in a book edited by Elizabeth Jameson and Susan Hodge "Writing the Range: Race, Class, and Culture in the Women's West". Footnote 57: "...she portrayed the femme fatale in Lancer's Spy (1937) and International Settlement (1938)." Elsewhere she's said to be a "Mata Hari" character.

If you do re-watch del Rio in Lancer Spy, I'd be curious to hear how you size her role up; and also hear why it's not a spy noir.

I'm not proposing that it's a noir or isn't, or that she's a femme fatale or isn't. I'm seeking to understand how these judgments are made.