List of ThreeColorSet

sample.cs

using System;
using System.Collections.Generic;
using System.Drawing;

namespace ConsoleApp1
{
    public class ThreeColorSet
    {
        public Color FirstColor { get; set; }

        public Color SecondColor { get; set; }

        public Color ThirdColor { get; set; }
    }


    public class MyClass
    {

        public List<ThreeColorSet> GetColorSets()
        {
            return new List<ThreeColorSet>
            {
                new ThreeColorSet
                {
                    FirstColor = Color.AliceBlue,
                    SecondColor = Color.Azure,
                    ThirdColor = Color.Aquamarine
                },
                new ThreeColorSet
                {
                    FirstColor = Color.Red,
                    SecondColor = Color.Green,
                    ThirdColor = Color.Blue
                }
            };
        } 
    }
}