Get the color of a Solid Brush object
#include <GDIPlus.au3>
_GDIPlus_BrushGetSolidColor ( $hBrush )
| $hBrush | Handle to a Brush object | 
| Success: | the brush color. | 
| Failure: | -1 and sets the @error flag to non-zero, @extended may contain GPSTATUS error code ($GDIP_ERR* see GPIPlusConstants.au3). | 
Search GdipGetSolidFillColor in MSDN Library.
#include <GDIPlus.au3>
#include <GUIConstantsEx.au3>
Example()
Func Example()
    Local $hGUI, $idLabel1, $idLabel2, $hGraphic, $hBrush1, $iClr1, $iClr2
    ; Create GUI
    $hGUI = GUICreate("GDI+", 345, 150)
    $idLabel1 = GUICtrlCreateLabel("", 2, 2, 150, 20)
    $idLabel2 = GUICtrlCreateLabel("", 202, 2, 150, 20)
    GUISetState(@SW_SHOW)
    Sleep(100)
    ; Start GDIPlus
    _GDIPlus_Startup()
    $hGraphic = _GDIPlus_GraphicsCreateFromHWND($hGUI)
    ; Create solid brush
    $hBrush1 = _GDIPlus_BrushCreateSolid()
    ; Get solid brush color
    $iClr1 = _GDIPlus_BrushGetSolidColor($hBrush1)
    ; Draw some graphics with the original brush color
    _GDIPlus_GraphicsFillEllipse($hGraphic, 25, 25, 100, 100, $hBrush1)
    ; Set new brush color (0xFFFF0000 = Red)
    _GDIPlus_BrushSetSolidColor($hBrush1, 0xFFFF0000)
    ; Get new solid brush color
    $iClr2 = _GDIPlus_BrushGetSolidColor($hBrush1)
    ; Draw some graphics with the new brush color
    _GDIPlus_GraphicsFillRect($hGraphic, 220, 25, 100, 100, $hBrush1)
    ; Write original brush color to Label1
    GUICtrlSetData($idLabel1, "Brush orignal color: " & Hex($iClr1))
    ; Write the new brush color to Label2
    GUICtrlSetData($idLabel2, "Brush new color: " & Hex($iClr2))
    ; Loop until the user exits.
    Do
    Until GUIGetMsg() = $GUI_EVENT_CLOSE
    ; Clean up resources
    _GDIPlus_BrushDispose($hBrush1)
    _GDIPlus_GraphicsDispose($hGraphic)
    _GDIPlus_Shutdown()
EndFunc   ;==>Example