George Catlin is low-key throughout, a quality associated with Tenebrous Sienna - deep shadows dominate the composition. Temperature is cool-dominant, with blue and green families claiming the largest areas. The absence of saturated colour is itself an expressive choice: this is a palette of restraint and atmosphere. At 50.5%, #181818 functions less as a colour accent and more as a complete atmospheric environment. Only 1.9% is devoted to #A0521F, yet that small allocation delivers the palette's entire chromatic tension. 63 units of value range underpin the palette's structural clarity: the eye always knows where light falls. The combination of low values, muted chroma, and compressed range is the signature of the Tonalist mode - painting as atmosphere. George Catlin's palette 6 carries its own internal logic while remaining in conversation with the artist's broader colour intelligence.