Alphonse Mucha is high-key - luminous, open, and weighted toward light. The palette achieves thermal balance - reds and blues, ochres and greens, each holding the other in check. Saturation is measured and controlled, giving the palette presence without visual aggression. The highest-chroma note - #A6532C - appears at just 6.0%, deployed as a precision accent against the quieter ground. At 51 units across the value scale, the palette keeps contrast readable without letting it dominate. Together these qualities point to the open-air Impressionist method: recording light rather than local colour. Alphonse Mucha's palette 4 carries its own internal logic while remaining in conversation with the artist's broader colour intelligence.