Changer la couleur d'un petit cercle (dot) contenues dans le radio bouton rouge?

J'ai pris l'OP du code VB comme base et avec un peu d'aide de MSDN sur l'utilisation de la PathGradientBrush venu avec cette derrived classe pour C#. Le vert et le rouge des boutons comme on le voit dans l'image ci-dessous sont à l'aide de mon code, les deux bleus sont la version régulière.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Drawing;
using System.Drawing.Drawing2D;
namespace WindowsFormsApplication1
{
public class ColouredRadioButton : RadioButton
{
//Fields
private Color m_OnColour;
private Color m_OffColour;
private Rectangle m_glint;
private Rectangle m_circle;
private PathGradientBrush m_flareBrush;
private Pen m_outline;
//Properties
public Color OnColour
{
get
{
return m_OnColour;
}
set
{
if ((value == Color.White) || (value == Color.Transparent))
m_OnColour = Color.Empty;
else
m_OnColour = value;
}
}
public Color OffColour
{
get
{
return m_OffColour;
}
set
{
if ((value == Color.White) || (value == Color.Transparent))
m_OffColour = Color.Empty;
else
m_OffColour = value;
}
}
//Constructor
public ColouredRadioButton()
{
//Init
m_circle = new Rectangle(2, 5, 7, 7 /*Magic Numbers*/);
m_glint = new Rectangle(3, 6, 4, 4  /*Magic Numbers*/);
m_outline = new Pen(new SolidBrush(Color.Black), 1F /*Magic Numbers*/);
//Generate Glint
GraphicsPath Path = new GraphicsPath();
Path.AddEllipse(m_glint);
m_flareBrush = new PathGradientBrush(Path);
m_flareBrush.CenterColor = Color.White;
m_flareBrush.SurroundColors = new Color[] { Color.Transparent };
m_flareBrush.FocusScales = new PointF(0.5F, 0.5F/*Magic Numbers*/);
//Allows for Overlaying
SetStyle(ControlStyles.SupportsTransparentBackColor, true);
BackColor = Color.Transparent;
}
//Methods
protected override void OnPaint(PaintEventArgs e)
{
//Init
base.OnPaint(e);
Graphics g = e.Graphics;
g.SmoothingMode = SmoothingMode.AntiAlias;
//Overlay Graphic
if (this.Checked)
{
if (OnColour != Color.Empty)
{
g.FillEllipse(new SolidBrush(OnColour), m_circle);
g.FillEllipse(m_flareBrush, m_glint);
g.DrawEllipse(m_outline, m_circle);
}
}
else
{
if (OffColour != Color.Empty)
{
g.FillEllipse(new SolidBrush(OffColour), m_circle);
g.FillEllipse(m_flareBrush, m_glint);
g.DrawEllipse(m_outline, m_circle);
}
}
}
}
}

Si vous êtes curieux et vous voulez le code de la grosse boule rouge que je l'utilise pour tester la brosse fonctionnalités, vous pouvez y aller...

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Drawing2D;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Paint(object sender, PaintEventArgs e)
{
e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
int Offset = 25;
int BoxSize = 100;
int GlintSize = (int)((double)BoxSize * ((double)3 / (double)4));
Rectangle Circle = new Rectangle(Offset, Offset, BoxSize, BoxSize);
Rectangle Glint = new Rectangle(Offset, Offset, GlintSize, GlintSize);
//Debug
//e.Graphics.FillRectangle(new SolidBrush(Color.Red), Circle);
//e.Graphics.FillRectangle(new SolidBrush(Color.BlueViolet), Glint);
//Generate Glint
GraphicsPath P = new GraphicsPath();
P.AddEllipse(Glint);
PathGradientBrush FlareBrush = new PathGradientBrush(P);
FlareBrush.CenterColor = Color.FromArgb(255, 255, 255, 255);
Color[] colors = { Color.Transparent };
FlareBrush.SurroundColors = colors;
e.Graphics.FillEllipse(new SolidBrush(Color.FromArgb(255, 255, 0, 0)), Circle);
e.Graphics.FillEllipse(FlareBrush, Glint);
e.Graphics.DrawEllipse(new Pen(new SolidBrush(Color.Black), 1F), Circle);
}
}
}