Option Explicit

Public Const WM_MOUSELEAVE As Long = &H2A3&
Public Declare PtrSafe Function TRACKMOUSEEVENT Lib "user32" Alias "TrackMouseEvent" ( _
          lpEventTrack As TRACKMOUSEEVENT) As Long

Public Type TRACKMOUSEEVENT
    cbSize As Long
    dwFlags As Long
    hwndTrack As LongPtr
    dwHoverTime As Long
End Type

Public Const TME_LEAVE As Long = &H2

Declare PtrSafe Function SetWindowLong Lib "user32" Alias "SetWindowLongPtrA" (ByVal hWnd As LongPtr, ByVal nIndex As Long, ByVal dwNewLong As LongPtr) As LongPtr

Declare PtrSafe Function CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal lpPrevWndFunc As LongPtr, ByVal hWnd As LongPtr, ByVal Msg As Long, ByVal wParam As LongPtr, ByVal lParam As LongPtr) As LongPtr

Private Const GWLP_WNDPROC = (-4)
Dim PrevProc As LongPtr
Public Track As TRACKMOUSEEVENT
Public NoRecursForm As Boolean

Public Sub Hook(ByVal frmHWnd As LongPtr)
    PrevProc = SetWindowLong(frmHWnd, GWLP_WNDPROC, AddressOf WindowProc)
End Sub

Public Sub UnHook(ByVal frmHWnd As LongPtr)
    SetWindowLong frmHWnd, GWLP_WNDPROC, PrevProc
End Sub

Public Function WindowProc(ByVal hWnd As LongPtr, ByVal uMsg As Long, ByVal wParam As LongPtr, ByVal lParam As LongPtr) As LongPtr
    
    If uMsg = WM_MOUSELEAVE Then

        If UserForm1.Image1.BackColor = vbGreen Then
           UserForm1.Image1.BackColor = vbRed
        Else
           UserForm1.Image1.BackColor = vbGreen
        End If
        
    End If
    
    WindowProc = CallWindowProc(PrevProc, hWnd, uMsg, wParam, lParam)
End Function

Sub Example()
    Load UserForm1
    UserForm1.Show
End Sub

Option Explicit

Private Declare PtrSafe Function FindWindowA Lib "user32.dll" (ByVal lpClassName As String, ByVal lpWindowName As String) As LongPtr
 
Private mlnghWnd As LongPtr
 
Public Property Get hWnd() As LongPtr
    hWnd = mlnghWnd
End Property
 

Private Sub UserForm_Initialize()
   StorehWnd
   Hook Me.hWnd
   With Track
       .cbSize = Len(Track)
       .dwFlags = TME_LEAVE
       .hwndTrack = Me.hWnd
       .dwHoverTime = 400
   End With
End Sub
 
Private Sub StorehWnd()
 
    Dim strCaption As String
    Dim strClass As String
 
    'class name changed in Office 2000
    If Val(Application.Version) >= 9 Then
        strClass = "ThunderDFrame"
    Else
        strClass = "ThunderXFrame"
    End If
 
    'remember the caption so we can
    'restore it when we're done
    strCaption = Me.Caption
 
    'give the userform a random
    'unique caption so we can reliably
    'get a handle to its window
    Randomize
    Me.Caption = CStr(Rnd)
 
    'store the handle so we can use
    'it for the userform's lifetime
    mlnghWnd = FindWindowA(strClass, Me.Caption)
 
    'set the caption back again
    Me.Caption = strCaption
 
End Sub

Private Sub UserForm_MouseMove(ByVal Button As Integer, ByVal Shift As Integer, ByVal X As Single, ByVal Y As Single)
    TRACKMOUSEEVENT Track
End Sub

Private Sub UserForm_QueryClose(Cancel As Integer, CloseMode As Integer)
    UnHook Me.hWnd
End Sub