Mouse Wheel on Title Bar (change color)

When I wheelscroll with position of mouse on the title bar of window, the window is disappeared and only titlebar of window is left. The question: how to change color of the titlebar of window at this moment (to red, for example)?

You can use FvwmEvent to change/toggle the colorset the window uses when it becomes shaded. This will then trigger each time a window is shaded and unshaded. Example configuration could look something like this

DestroyModuleConfig FE-ShadeColorset: *
*FE-ShadeColorset: Cmd Function
*FE-ShadeColorset: windowshade SetShadeColorset
*FE-ShadeColorset: dewindowshade SetUnShadeColorset

DestoryFunc SetShadeColorset
AddToFunc SetShadeColorset
+ I ThisWindow (Shaded) WindowStyle Colorset X, HilightColorset Y, BorderColorset X, HilightBorderColorset Y

DestoryFunc SetUnShadeColorset
AddToFunc SetUnShadeColorset
+ I ThisWindow (!Shaded) WindowStyle Colorset X, HilightColorset Y, BorderColorset X, HilightBorderColorset Y

Here FvwmEvent triggers the appropriate function to change the colorset used. Last you need to run the FvwmEvent module to make use of this (could run from StartFunction)

Module FvwmEvent FE-ShadeColorset

Excellent! Thank you very much. Which I wanted is realized by X=Y=11 in Shaded and X=1, Y=0 in !Shaded. In my system 0 - Default, 1 - Inactive Windows and Colorset 11 fg #ffffff, bg #1a6e99, hi #ffffff, sh #ffffff, Plain, NoShape. If a window is shaded (the titlebar only) it has blue color in active and nonactive state, If non-shaded it has normal colors. This is good to see which windows are shaded.