How to Change GIMP Sample Points Color Format

The Sample Points dialog in GIMP allows you to monitor precise color values at designated coordinates on your canvas in real time. Depending on your project requirements, you may need these values displayed as raw pixel values, standard RGB numbers, or HSV metrics. This guide explains how to access the Sample Points dialog and switch the color readout format between Pixel, RGB, and HSV.

Step 1: Open the Sample Points Dialog

To manage sample points, ensure the dedicated dialog window is visible:

  1. Go to the top menu and select Windows.
  2. Hover over Dockable Dialogs.
  3. Click on Sample Points to open the panel.

Step 2: Create a Sample Point (If Needed)

If you do not already have sample points placed on your image:

  1. Ensure the rulers are visible by going to View > Show Rulers (or press Ctrl + Shift + R).
  2. Hold the Ctrl key, click inside either the horizontal or vertical ruler, and drag the cursor onto your canvas.
  3. Release the mouse button to place a point. The Sample Points dialog will now list your new point (e.g., "Sample Point 1").

Step 3: Switch the Color Readout Format

Each active sample point in the dialog can have its color format set independently:

  1. Locate the entry for your sample point inside the Sample Points dialog.
  2. Click the drop-down menu button located directly to the right of the sample point number (it often defaults to Pixel or RGB (0-255)).
  3. From the list of available color representations, select your desired format:
    • Pixel: Displays the raw channel data based on the image's current color precision and mode.
    • RGB (0-255): Displays red, green, and blue values on the standard 8-bit scale from 0 to 255.
    • RGB (%): Displays red, green, and blue values as percentages from 0% to 100%.
    • HSV: Displays the color broken down into Hue (degrees from 0° to 360°), Saturation (percentage), and Value (percentage).
    • Hex: Displays standard hexadecimal HTML/CSS color notation.

The values in the dialog will update immediately to reflect the selected color model. You can assign different readout formats to different sample points simultaneously within the same dialog.