Atelier Nadar - Fly scene from Offenbach's Orphée aux enfers with Jeanne Granier as Eurydice and Eugène Vauthier as Jupiter, 1887 revival, wide-angle shot

Jeanne Granier (Eurydice) and Eugène Vauthier (Jupiter) in the famous fly scene from Jacques Offenbach's Orphée aux enfers. Albumen print, 10.5 x 14.5 cm. This was the 1887 revival cast.
A gorgeous colourised version by Wilfredor is available at File:Atelier Nadar - Fly scene from Offenbach's Orphée aux enfers with Jeanne Granier as Eurydice and Eugène Vauthier as Jupiter, 1887 revival, wide-angle shot-Colorized.jpg.
Advantages of uncolourised

Colourization involves a bit of speculation, so this may have higher encyclopedic value.
Advantages of colourised

Makes elements pop out.
Gorgeous and artistic.
If the specific production doesn't matter (posters, illustrations of the show as a whole, etc), has no disadvantages
Fun fact: If I'm not horribly mistaken, those wings are pretty clearly drawn on after the photo was taken, likely because the real props wouldn't stay still long enough.