how to set opacity in panels in C# form code example

Example: how to make a panel see through in vs form

this.OrganizationMenuPanel.BackColor = System.Drawing.Color.Transparent;
            this.OrganizationMenuPanel.Controls.Add(this.button16);
            this.OrganizationMenuPanel.Controls.Add(this.button15);
            this.OrganizationMenuPanel.Controls.Add(this.button14);
            this.OrganizationMenuPanel.Controls.Add(this.button13);
            this.OrganizationMenuPanel.Controls.Add(this.button12);
            this.OrganizationMenuPanel.Controls.Add(this.button11);
            this.OrganizationMenuPanel.Controls.Add(this.button10);
            this.OrganizationMenuPanel.Controls.Add(this.button9);
            this.OrganizationMenuPanel.Controls.Add(this.button8);
            this.OrganizationMenuPanel.Location = new System.Drawing.Point(148, 148);
            this.OrganizationMenuPanel.Name = "OrganizationMenuPanel";
            this.OrganizationMenuPanel.Size = new System.Drawing.Size(171, 372);
            this.OrganizationMenuPanel.TabIndex = 4;
            this.OrganizationMenuPanel.Visible = false;
            this.OrganizationMenuPanel.Leave += new System.EventHandler(this.OrganizationMenuPanel_Leave);
            this.OrganizationMenuPanel.MouseEnter += new System.EventHandler(this.OrganizationMenuPanel_MouseEnter);
            this.OrganizationMenuPanel.MouseLeave += new System.EventHandler(this.OrganizationMenuPanel_MouseLeave);
            this.OrganizationMenuPanel.MouseMove += new System.Windows.Forms.MouseEventHandler(this.OrganizationMenuPanel_MouseMove);