Index: drivers/wxwidgets_dc.cpp
===================================================================
--- drivers/wxwidgets_dc.cpp	(revision 12270)
+++ drivers/wxwidgets_dc.cpp	(working copy)
@@ -164,6 +164,9 @@
 //--------------------------------------------------------------------------
 void wxPLDevDC::FillPolygon( PLStream *pls )
 {
+	//give basic support to entirely transparent colour
+	if(m_dc->GetBrush().GetColour().Alpha()==0) return;
+
     wxPoint *points = new wxPoint[pls->dev_npts];
 
     for ( int i = 0; i < pls->dev_npts; i++ )
@@ -239,9 +242,10 @@
 //--------------------------------------------------------------------------
 void wxPLDevDC::SetColor0( PLStream *pls )
 {
-    m_dc->SetPen( *( wxThePenList->FindOrCreatePen( wxColour( pls->curcolor.r, pls->curcolor.g, pls->curcolor.b ),
+	//Many wxDCs do't support alpha, but a few do (Specifically OSX DCs and wxSVGFileDC) so use it in case
+    m_dc->SetPen( *( wxThePenList->FindOrCreatePen( wxColour( pls->curcolor.r, pls->curcolor.g, pls->curcolor.b, pls->curcolor.a ),
                          pls->width > 0 ? pls->width : 1, wxSOLID ) ) );
-    m_dc->SetBrush( wxBrush( wxColour( pls->curcolor.r, pls->curcolor.g, pls->curcolor.b ) ) );
+    m_dc->SetBrush( wxBrush( wxColour( pls->curcolor.r, pls->curcolor.g, pls->curcolor.b, pls->curcolor.a ) ) );
 }
 
 
@@ -252,9 +256,10 @@
 //--------------------------------------------------------------------------
 void wxPLDevDC::SetColor1( PLStream *pls )
 {
-    m_dc->SetPen( *( wxThePenList->FindOrCreatePen( wxColour( pls->curcolor.r, pls->curcolor.g, pls->curcolor.b ),
+	//Many wxDCs do't support alpha, but a few do (Specifically OSX DCs and wxSVGFileDC) so use it in case
+    m_dc->SetPen( *( wxThePenList->FindOrCreatePen( wxColour( pls->curcolor.r, pls->curcolor.g, pls->curcolor.b, pls->curcolor.a ),
                          pls->width > 0 ? pls->width : 1, wxSOLID ) ) );
-    m_dc->SetBrush( wxBrush( wxColour( pls->curcolor.r, pls->curcolor.g, pls->curcolor.b ) ) );
+    m_dc->SetBrush( wxBrush( wxColour( pls->curcolor.r, pls->curcolor.g, pls->curcolor.b, pls->curcolor.a ) ) );
 }