Shape Rotation and background Color

MapWinGIS
1

Hi,
I would reproduce the image reported below.
site

I’m using an image like this
triangle2

My questions are:

  1. How can I change background color of picture?
  2. How can I rotate shape?

This is my code only with two azimuth 50° and 150°:

Dim sf As New Shapefile()
sf.CreateNewWithShapeID("", ShpfileType.SHP_POINT)
sf.CollisionMode = tkCollisionMode.AllowCollisions
Dim img As New Image
img.Open("C:\temp\triangle2.png", ImageType.PNG_FILE, False, Nothing)

Dim utils As New Utils

Dim ct = sf.Categories.Add("site")
Dim opt = ct.DrawingOptions
opt.PointType = tkPointSymbolType.ptSymbolPicture
opt.FillType = tkFillType.ftPicture
opt.FillColor = utils.ColorByName(tkMapColor.Yellow)
opt.Picture = img

Dim pnt As New Point()
pnt.x = x 'longitude
pnt.y = y 'latitude

Dim shp As Shape = New Shape
shp.Create(ShpfileType.SHP_POINT)
shp.AddPoint(x, y)
shp.Rotate(x, y, 50)

Dim shp1 As Shape = New Shape
shp1.Create(ShpfileType.SHP_POINT)
shp1.Rotate(x, y, 150)
shp1.AddPoint(x, y)

sf.EditAddShape(shp)
sf.EditAddShape(shp1)
sf.StopEditingShapes()

My issues:
First point:
Background color doesn’t affect with code

opt.FillColor = utils.ColorByName(tkMapColor.Yellow)

Second Point:
Rotation of shape doesn’t affect.
Maybe a solution is to create several categories each one for a single azimuth (from 0° to 359°) like this:

Dim ct = sf.Categories.Add("site")
Dim opt = ct.DrawingOptions
opt.PointType = tkPointSymbolType.ptSymbolPicture
opt.FillType = tkFillType.ftHatch
opt.FillColor = utils.ColorByName(tkMapColor.Yellow)
opt.Picture = img
opt.PointRotation = 50

ct = sf.Categories.Add("site1")
opt = ct.DrawingOptions
opt.PointType = tkPointSymbolType.ptSymbolPicture
opt.FillType = tkFillType.ftHatch
opt.FillColor = utils.ColorByName(tkMapColor.Yellow)
opt.Picture = img
opt.PointRotation = 150

and afterwards I assign each categories to relative shape (i.e. TrackCars.cs)
but I don’t know if is the best solution

How can I proceed?
Thank in advanced
gio