private void _aNumeric_ValueChanged(object sender, EventArgs e)
{
_alphaPicker.AlphaChanged -= _alphaPicker_AlphaChanged;
_alphaPicker.Alpha = (float)Convert.ToDouble(_aNumeric.Value / 255);
_alphaPicker.AlphaChanged += _alphaPicker_AlphaChanged;
_color = Color.FromArgb((int)(_alphaPicker.Alpha * 255), Color);
ColorChanged(this, null);
}