A picture speaks a thousand words. At the moment both the enabled and disabled state are gray, just different shades. Please make the enable state stand out a little more by using color, see my crude mock-up below:
Once the button on/off indicator is colored blue as shown above, there won't be any need for the following prompt in the middle of the screen, which IMO is intrusive and distracting:
If you take a look at EQ plugins such as FabFilter Pro Q 3, when the bypass button is engaged there is no intruisve banner across the middle, but the state of the on/off buttons is made ultra clear by means of eye-catching colour.