Customise Eto TreeGridView appearance

Hello, I’m currently using a TreeGridView control with expandable items in a Rhino plugin using an Eto panel.

The expander arrow is painted black when expanded, and white with a light gray border when not expanded.

If the item row is selected, the collapsed item’s arrow is barely visible, due to the selection background colour (see image).

Expander arrows

I would like to customise the expander arrow’s appearance so that it’s always painted black.

The Eto TreeGridView class does not allow to modify the appearance of the control or sub-controls, but, as far as I have understood, there is a way to access the native platform’s object, where some UI/appearance changes can be applied (e.g. access the underlying System.Windows.Forms.DataGridView if running on Win).

The process to do so is not quite clear to me though.
Do I need to add a reference to Eto.Platform.Windows to use TreeGridViewHandler?
I tried doing so, but adding the reference causes name clashes with Rhino.UI.

Any help?

@curtisw - is this something you can help with?