Here is the code to insert on the Chart1 object code window.

Dim keepA As Long, keepB As Long

Private Sub Chart_MouseMove(ByVal Button As Long, ByVal Shift As Long, ByVal x As Long, ByVal y As Long)

Dim ws1 As Worksheet, ws2 As Worksheet
Dim searchModel As Range, searchColor As Range
Dim searchComment As Range, lastRow As Long
Dim ID As Long, a As Long, b As Long
    
    Me.GetChartElement x, y, ID, a, b
    If a = keepA And b = keepB Then Exit Sub
    Select Case ID
        Case 3
            Set ws1 = Sheet2
            myColor = ws1.Cells(4, a + 1)
            myModel = ws1.Cells(b + 4, 1)
                
            Set ws2 = Sheet3
            lastRow = ws2.Cells.SpecialCells(xlLastCell).Row
            
            Set searchModel = Range(ws2.Cells(1, 1), ws2.Cells(lastRow, 1))
            Set searchColor = Range(ws2.Cells(1, 2), ws2.Cells(lastRow, 2))
            Set searchComment = Range(ws2.Cells(1, 5), ws2.Cells(lastRow, 5))

            'MsgBox myColor, vbOKOnly, myModel
            For i = 1 To lastRow
                If searchModel.Cells(i) = myModel Then
                    If searchColor.Cells(i) = myColor Then
                        MsgBox searchComment.Cells(i)
                        Exit For
                    End If
                End If
            Next i
            
            keepA = a
            keepB = b
        Case Else
            'do nothing
    End Select
   
End Sub
keepA and keepB are declared outside of the Event procedure so that you do not get the message box again until you mouse over a different model or different color.

You would want to replace the MsgBox with something more elaborate, I assume.