Color Consistency with Hexadecimal?


Today’s Question: I use a specific color to add a watermark to my photos. I was told that if I use a hexadecimal value to choose my color, the color would be consistent whether I’m sharing my photos online or making a print. Is this true even if I’m using the sRGB color space for online images and the ProPhoto RGB color space for photos I’m printing?

Tim’s Quick Answer: No, a single hexadecimal (or RGB or HSL) color value will not produce the same color result for images with different color spaces. You would need to identify a specific color value for each color space in order to ensure the color will match across multiple color spaces.

More Detail: The color models used most frequently by photographers are device-dependent color models, meaning the actual color you will achieve with a given set of color values will vary depending on how the color is reproduced. For example, the RGB color model is used by many monitor displays, but each unique display might interpret individual color values in different ways. One of the key reasons for this type of variation is that the primary colors (such as red, green and blue for RGB) may be slightly different among different devices.

One of the side-effects of a device-dependent color model is that color values by themselves don’t actually represent a single specific color. You need a color profile to define what the color means. And for each different color profile, the same color values will generally produce at least slightly varied colors. So in order to ensure the same color across various output methods, you need to either use the same color space profile for all of that output, or you need to define the color values based on the specific profile being used.

There are two basic options you could use here. First, you could make sure to create the source image including your colored watermark as a “master” image, and then create derivative images from that single master. After creating a copy of the master image, for example, you could convert the copy to the sRGB color space and otherwise prepare that version for online sharing. You could then use the master as the basis for a print, using proper color management for the printing process. This would ensure the colors match as closely as possible for both types of output.

The other option would be to identify the appropriate hexadecimal (or RGB) color values for each color space you’ll use. Start with an image that includes the desired color in the correct color space, and of course note the color values for that color based on that color space. Then convert the image to the other color space you need to use (such as sRGB) and note the resulting (and different) color value for the color you’re using. You could then use those noted color values for different color spaces, setting the appropriate value based on the color space you are currently working in.

Note, by the way, that hexadecimal color values are really just a shorthand for RGB color values and are commonly used on the web for presenting colors online. You can essentially use hexadecimal or RGB values for colors interchangeably, keeping in mind that you must define a specific color space in order for those color values to have an accurate meaning in terms of the color you’re looking for.

You can learn more about color management in general with my course “Color Management for Photographers”, which you can get for half off if you use this link to get started: