The Horsehead and Flame Nebulae
The region is about 1,375 light-years away and the horse's head is mainly a large cloud of interstellar dust obscuring the stars and nebulous gasses. The red/orange color originates from hydrogen gas predominantly behind the nebula, ionized by the nearby bright star Sigma Orionis above the horse's head in the upper right (blue double star). There is an additional abundance of hydrogen dust throughout this region which glows in a red color caused by the radiation of nearby stars.
The bright blue star above the Flame Nebula is Alnitak, the left-most star of the 3 stars of Orion's belt. The bright spots to the lower left of the "Horsehead) are new stars forming.

Orion EON 130mm Triplet Refractor with 0.8x Field Reducer
Camera: ZWO 1600mm pro monochrome
Filters: Hydrogen-alpha, Sulfur 2, and UV/IR cut

Stacked in Deep SkyStacker ... processed in PixInsight and Photoshop
Color combination:
Red= 50/50 blend of S2 and Ha
Green= Ha
Blue= UV/IR cut (Luminance)