passing control indexer by reference to method to change its property - methods

Question

i have made a program, which include a lot of controls. The controls would be showed and hided according to the choice of the user. That means that controls overlapped on each other at design time. now i want to change the forecolor and backcolor of all controls at design time. but i founded so hard to accomplish this task, because all the control overlapping each other. so I decided to make a for loop method to iterate the controls in the form and then check each control in turn whether it has controls. when the control has also controls in it, I call the same method and pass the control to it to change the properties for the subcontrols too. The method like so:
void setColor(ref Control con)
{
con.BackColor= System.Drawing.Color.Black;
con.ForeColor=System.Drawing.Color.Yellow;
if (con.Controls.Count > 0) { setColor(ref con); }
}
so my Form include tabControl with multiple tabPages. I iterate the tabPages and wanted to pass it to this method, but I become error "Indexer may not be passed as an out or ref parameter"
I pass it so: setColor(ref tabControl1.Controls[i]);
can you please help me to solve this problem?

Answer 1

I have resolved the problem.
I have removed the "ref" from method and wrote the method simply like the following:
void SetColor(Control con)
{
con.BackColor = System.Drawing.Color.Black;
con.ForeColor = System.Drawing.Color.Yellow;
if (con.Controls.Count > 0)
{
for (int i=0; i<con.Controls.Count;i++)
SetColor(con.Controls[i]);
}
}
and call it so: setColor(this.Controls[i]);