tintColor property
The tint color of a picture fill symbol layer.
The tint color is applied to the entire image by multiplying each RGB color channel in the image by the corresponding color channel of the tint color. The default tint color is white with 100% opacity, i.e. RGBA(255, 255, 255, 255). Applying a tint color with transparent black (RGBA(0, 0, 0, 0)) draws the image as originally authored.
When retrieving the tint color from a symbol, the color that is shared among all color unlocked symbol layers is returned. If there is no common color across the symbol layers (meaning one or more color unlocked layers have different tint colors), transparent black (RGBA(0, 0, 0, 0)) is reported as the color of the symbol. Likewise, applying a tint color to a symbol will affect all the color unlocked symbol layers within the MultilayerSymbol. Applying a transparent black (RGBA(0, 0, 0, 0)) on the symbol does not affect the tint color of its constituent PictureFillSymbolLayer.