🎨 Excel-Style Color Picker for WinForms

A comprehensive, Excel-style color picker component for C# WinForms applications. This user control provides a modern and feature-rich interface for color selection, designed to be easily integrated as a drop-down from a button.

✨ Demo

🚀 Features

• 🌈 Circular Color Wheel: An intuitive wheel for selecting hue and saturation.
• 🎚️ Brightness Slider: A vertical slider to control the selected color's brightness (HSV Value).
• ▦ Standard Palette: A pre-defined grid of theme colors, similar to Microsoft Office applications.
• 🔢 Live Value Display: Instantly see the selected color's values in HEX, RGB, and CMYK formats.
• 🛡️ Safety Modes:
  • Web-Safe Mode: Snaps all color selections to the nearest web-safe color.
  • Print-Safe Mode: Snaps all selections to their nearest CMYK-safe equivalent, ensuring better color fidelity in print.
• ⚠️ Safety Warnings: Visual cues indicate if the current color is not web-safe or print-safe, with a one-click option to fix it.
• 👀 Original vs. New Color Preview: Easily compare the newly selected color with the original one.
• ⌨️ Full Keyboard Navigation: All elements of the control are fully accessible and navigable using the keyboard.
• 🧩 Easy Integration: Simply add the ExcelColorPopupButton to your form. No other setup is required.
• 📦 Self-Contained: The control is written entirely in C# and relies only on the standard .NET System.Windows.Forms and System.Drawing libraries. No external dependencies are needed.

🛠️ Getting Started

📋 Prerequisites

You need a .NET project with Windows Forms support. This component has been designed with .NET Framework 4.x or .NET 5/6/7/8 and later in mind.

⚙️ Installation

1. Clone this repository or download the source code.
2. Add the C# source files (ExcelColorPopupButton.cs, ExcelColorDropDownControl.cs, etc.) to your WinForms project.
3. Rebuild your project.
4. The ExcelColorPopupButton control should now appear in the Visual Studio Toolbox, ready to be dragged onto your forms.

💡 How to Use

The easiest way to use the color picker is with the ExcelColorPopupButton control.

1. 🖱️ Add the Button to Your Form:

   • After rebuilding your project, find the ExcelColorPopupButton in your Visual Studio Toolbox.
   • Drag and drop it onto your form.

2. ⚡ Handle the ColorChanged Event:

   • Select the button on your form and go to the Events tab in the Properties window.
   • Double-click the ColorChanged event to create a handler.
   • Use this event to get the newly selected color and apply it to other controls or objects in your application.

// Example: Change a Panel's background color when a new color is selected.
private void excelColorPopupButton1_ColorChanged(object sender, EventArgs e)
{
    // Get the selected color from the button's property
    Color newColor = excelColorPopupButton1.SelectedColor;

    // Apply it to another control
    panelToChange.BackColor = newColor;

    // You can also get the value as a string for display
    this.Text = $"Selected Color: {newColor}";
}

// You can also set the initial color of the button in your Form's Load event
private void Form1_Load(object sender, EventArgs e)
{
    excelColorPopupButton1.SelectedColor = Color.CornflowerBlue;
}

🔍 Code Overview

The project is structured into several key classes:

• 🔘 ExcelColorPopupButton: The main Button control that you add to your form. It handles painting the color preview and the drop-down arrow, and it manages the display of the ExcelColorDropDown.

• 🔽 ExcelColorDropDown: A custom ToolStripDropDown that acts as a borderless window to host the main color picker user control.

• 🎛️ ExcelColorDropDownControl: The core UserControl that contains all the UI elements: the circular picker, brightness slider, color grid, text boxes, and checkboxes. It manages all the internal logic for color updates and state changes.

• 🌈 CircularColorPicker: A custom control that renders the HSL color wheel and handles user input (mouse and keyboard) for selecting hue and saturation.

• 🎚️ BrightnessSlider: A custom control for the vertical brightness (value) slider.

• 🔧 ColorUtils: A static helper class containing methods for color model conversions (RGB, HSV, HSL, CMYK) and color safety checks.

• 📝 VerticallyCenteredTextBox: A small enhancement of the standard TextBox to vertically center its text.

• 🖌️ DoubleBufferedPanel: A simple Panel with double-buffering enabled to prevent flicker in the color grid.

📜 License

This project is licensed under the MIT License. See the LICENSE file for details.