For booleans I tend to prefer using “Enable/Disable”. In this example, “Disable Flash” with a checkbox that is clearly in an “Enabled” state can reduce ambiguity. Alternatively, displaying the state and using tooltips that describe the action can be great, but falls apart on mobile devices.
That leads to the extremely common confusion of if "disable flash" is a description of what you will do when you interact with the control (the verb describes the action to be done), or a description of the current state (it's a "yes, disable flash" confirmation). Both are common. Some apps even use both on different controls.
Compare that to a checkbox next to "Flash is disabled". Or a toggle. Or a button. The control and its vague state or bad color blindness choices doesn't even matter if you're clear with your words.
