This is OS29D, a delicately colored nebulous region in Orion illuminated by the belt stars Anilam and Mintaka (or both).
I have incorporated almost 4 hours of Ha data to bring out the subtle nebulosity in this wide field image.

PlaneWave 12.5″ astrograph with an ST11000 camera, Astrodon filters, and ASA gearless DDM-85 mount. F/5 Ha RGB (27/8min Ha, 10/8 min each RGB. All 1×1 ).