Can I use a transparent version of the MUI AppBar with the original color from theme?

Question

If I have the following

<AppBar
  elevation={0}
>

The app bar will be blue. I would like to make that blue transparent while allowing me to update the theme to a different color and still have it show up as that color only with transparency. I tried the following...

<AppBar
  elevation={0}
  sx={{
    backdropFilter: "blur(10px)", // Add this line
    backgroundColor: 'transparent', // And this line
  }}
>

But of course this doesn't maintain the theme color and just makes it plain transparent.

Can I make a MUI app bar transparent with the color from the theme still added?