Colour Value (Grayscale) Checker for Painting
Convert any colour to its grayscale value to check tonal contrast for a painting, drawing or design, using the same value-checking approach painters use when squinting at a reference photo.
Enter a Colour
Value Result
Original
Grayscale Value
Value Scale (0-10)
How to Use This Tool
Enter a colour using the picker or by typing a hex code. The tool converts it to its grayscale value using the same relative luminance formula used for accessibility contrast checking, then shows where that value sits on a 0 to 10 value scale.
Example
A deep blue such as #2547A0 converts to a fairly dark grayscale value, useful for identifying it as a shadow tone in a value study, even though the hue itself feels vivid and saturated.
Why Value Matters More Than Hue
Many painting teachers argue that getting the values right in a painting matters more than getting the exact hue right, since a well-organised range of light and dark shapes reads clearly even from a distance or in black and white. This tool lets you check the value of a colour in isolation, the same way squinting at a reference photo helps you see values by reducing colour information.
Using This Alongside a Painting
Check the value of your key colours before you start painting to plan your lightest lights and darkest darks, or use it partway through a piece to confirm your shadow and highlight colours sit at meaningfully different values.
Frequently Asked Questions
What does this tool do?
It converts a colour to its grayscale value and shows where that value sits on a light-to-dark scale, helping you check tonal contrast for a painting or design.
What is value in painting?
Value refers to how light or dark a colour is, independent of its hue or saturation. It is often considered one of the most important elements of a strong painting.
How is the grayscale value calculated?
It uses the standard relative luminance formula, which weights red, green and blue differently to match how the human eye perceives brightness.
Is this the same as the Tints & Shades Generator?
No, the Tints & Shades Generator creates lighter and darker versions of a hue, while this tool measures the existing value of a colour and converts it to pure gray.
Why do two different colours sometimes have a similar value?
Because value only measures lightness or darkness, two colours with different hues, like a mid-blue and a mid-red, can still share a very similar value.
Can I use this for digital painting or photography?
Yes, checking value is a common technique across traditional painting, digital art and photography for planning strong tonal contrast.
What does the highlighted swatch on the value scale mean?
It marks where your chosen colour sits on the 0 to 10 value scale, making it easy to compare against pure black, pure white and middle gray.
Is this tool free to use?
Yes, this tool is completely free to use with no sign-up required.
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Explore Painting KitsGrayscale value is calculated using the standard WCAG relative luminance formula, a widely used approximation of perceived brightness, rather than a physical light-measurement device.