appkit:color

(appkit:color r g b &optional (alpha 1.0))

Answers an NSColor with those red, green and blue components, each 0-255, and that alpha (0.0 clear, 1.0 opaque). It is what every colour argument in the package takes -- a window's :background, a panel's :fill, a label's :color, appkit:set-color. Part of the appkit package, a Cocoa widget layer written in rontolisp over objc and loaded on first use: macOS (java -jar, the rontolisp binary, or a compiled .class / .jar; never a .wasm), with a display. See the macOS GUI guide.

CL-USER> (defvar *amber* (appkit:color 255 176 74))
CL-USER> (appkit:label *win* "007" :x 20 :y 20 :width 96 :height 44 :color *amber*)
#<objc RontoLispAppKitLabel>