C#

class ControlTextColorChangedEventArgs : System.EventArgs
    {
        private Color _color;

        public Color Color
        {
            get { return _color; }            
        }
        public ControlTextColorChangedEventArgs(Color color)
        {
            this._color = color;
        }
    }

public partial class UserControl1 : UserControl
    {
        public delegate void UserEventHandler(object sender, ControlTextColorChangedEventArgs e);
        public event UserEventHandler ControlTextColorChanged;

        private string _text;
        private Color _color;        
        
        public string ControlText
        {
            get { return _text; }
            set 
            { 
                _text = value;
                this.OnPaint(new PaintEventArgs(this.CreateGraphics(), this.ClientRectangle));                
            }
        }

        public Color ControlTextColor
        {
            get { return _color; }
            set 
            { 
                _color = value;
                this.OnPaint(new PaintEventArgs(this.CreateGraphics(), this.ClientRectangle));
                this.OnControlTextColorChanged(new ControlTextColorChangedEventArgs(this.ControlTextColor));
            }
        }

        public UserControl1()
        {
            InitializeComponent();
            this._color = Color.Black;            
            this.ControlText = string.Empty;
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            if (this.ControlText != string.Empty)
            {
                e.Graphics.DrawString(this.ControlText, new Font("tahoma", 10), new SolidBrush(this.ControlTextColor), new PointF(this.Width / 2, this.Height / 2));
            }
            //base.OnPaint(e);
        }

        public virtual void OnControlTextColorChanged(EventHandling.ControlTextColorChangedEventArgs e) // error occure in this line
        {
            ControlTextColorChangedEventArgs handler = ControlTextColorChanged;
            if (handler != null)
            {
                handler(this, e);
            }
        }
    }

Inconsistent accessibility: parameter type 'EventHandling.ControlTextColorChangedEventArgs' is less accessible than method 'EventHandling.UserControl1.OnControlTextColorChanged(EventHandling.ControlTextColorChangedEventArgs)'