Beginner WinForms project with CSV loading, ComboBox data, dynamic controls and deletion

https://codereview.stackexchange.com/ should draw more attention to itself.... (sigh)

"... whether this structure is acceptable for a small WinForms learning project,"

I don't think you'll find 2 people that define 'acceptable' the same :)

But as a baseline, I'd say you should strive to avoid known anti-patterns or in places where an anti-pattern is used on purpose for simplicity, you should point that out and reference to documentation for "proper" alternatives.

An example would be CSV-Handling. In a production-grade codebase, you'll probably want to use a well-established library to allow you to focus on the application's business, not the csv-handling side-hustle. In a teaching project, though, you might want to adress the very problems and obstacles the usage of a dedicated library eliviates you from and you also might want to not make your example project teach that librarie's API (which would cause maintenance obligations on your part later on), so you present self-coded csv handling. You see where this is going...

Another thing is comments: In a real-world app, you'll want to have "self-documenting" code and keep explicit comments to a required minimum. In a teaching project, assuming people that are new to a lot of the tech involved, you'll probably want to add comments that would otherwise be judged as "yeah, obviously. I can see that, duuuh" - Explaining choices, where conventions have been applied and which ones and how, where docs can be found, where counterparts to things can be found (think Events and Handlers, e.g.) ...

Apart from that, I'd say what is 'acceptable' really depends on the skill-level of your targeted audience and what the focus is.

Thank you, this helps a lot. As a beginner programmer, it is really useful to see different opinions and better ways to structure small WinForms projects like this.

private void Form1_Load(object sender, EventArgs e)
{
    LoadColors("adatok.txt");
}
private void LoadColors(string fileName)
{
    colors.Clear();
    comboBox1.Items.Clear();
    string[] lines = File.ReadAllLines(fileName);
    foreach (string line in lines)
    {
        string[] parts = line.Split(',');
        ColorData color = new ColorData(
            parts[0],
            int.Parse(parts[1]),
            int.Parse(parts[2]),
            int.Parse(parts[3])
        );
        colors.Add(color);
        comboBox1.Items.Add(color);
    }
}

The application automatically reads the TXT/CSV file at startup, stores the parsed data in custom objects, and displays the loaded items inside a ComboBox.

if you define a class with a constructor, you can get from the csv to a list in one simple line like this

List myList = File.ReadLines(csv_file).Skip(1).Select(line => new myObject(line.Split(","))).ToList();