An AppleScript to convert a CMYK file to RGB using the ColorSync Utility. For some reason this works while sips --matchToWithIntent leaves the file all washed out and CMYKish. This script assumes a CMYK image is already open and the top window in ColorSync. I use it in combination with Automator.

cmyk2rgb.applescript

tell application "System Events"
	tell process "ColorSync Utility"
		set visible to true
		tell pop up button 1 of group 1 of front window
			click
			tell menu 1
				click menu item "Match to Profile"
			end tell
		end tell
		tell menu button 1 of group 1 of front window
			click
			tell menu 1
				click menu item "Display"
				tell menu item "Display"
					tell menu 1
						click menu item "sRGB IEC61966-2.1"
					end tell
				end tell
			end tell
		end tell
		tell pop up button 2 of group 1 of front window
			click
			tell menu 1
				click menu item "Perceptual"
			end tell
		end tell
		tell button "Apply" of group 1 of front window
			click
		end tell
		set frontmost to true
		keystroke "s" using {command down}
		keystroke "w" using {command down}
	end tell
end tell