Question: Explore command with an additional plot

Dear Maple users

I have created a simple Explore command in order to display what happens with a Planck curve when the temperature T increases - using the slider. Especially I would like to show how the maximum of the curve lies in relation to the visible spectrum from 400-700 nm, that is from 4*10^-7 to 7*10^-7. My idea was to somehow have this wavelength interval representing the visible spectrum displayed behind the Planck curve as a vertical rectangle. If it was a fixed plot, I could do it using the display command, but is it possible to add an extra plot to an Explore command?

I have uploaded the temporary Maple file and an image to show my intention (I don't expect the coloring ...)

Planck_curve.mw

Maybe someone can help?

Kind regards,

Erik V.