The rules for mobile design and mobile SEO aren’t completely different from the rules applicable to desktop sites but it is all the minor differences that make a designer’s life hard. These differences are present in all aspects of mobile design and the process of choosing the colors for your mobile site isn’t an exception.
Reuse Your Desktop Color Palette
When I say that the process of choosing the colors for your mobile site is different, don’t take it that it has nothing to do with the standard process you know from desktop sites. In fact, you seldom have to start from scratch but instead reuse your desktop color palette. This might seem like a lazy approach but in fact it is much superior in almost every aspect to choosing your colors from scratch.
For instance, if you want to ensure consistency between your mobile site and its desktop counterpart, the best you can do is use a stripped down version of the color palette of your desktop site. All you have to do is remove the colors for the site components you won’t be using on your mobile site, make sure that they display well on your target mobile devices (you might need to replace some of the colors, if they are too fancy to use on a mobile or if the contrast is unsafely low), and you are ready to go.
However, it is also totally acceptable to start your mobile site from scratch rather than make it a stripped down version of your main site. The most common case for this is when your mobile site has a very different functionality from your desktop site. Of course, even in this case you can use a modified version of the color palette from your main site but if due to various reasons this is not possible, you need to create your separate mobile color scheme.
In any case, when you choose the colors for your mobile website, the technical limitations of mobile devices are a very important consideration to keep in mind.
Keep in Mind the Technical Limitations of Mobile Devices
Mobile devices get more and more powerful day by day but still in terms of technical abilities, they are far behind contemporary PC displays. For instance, mobiles with monochrome displays are almost history, though you can occasionally find people who use them. You might laugh at the idea to design with these devices in mind but the USE_OF_COLOR Human Test (“Browse the page in a monochrome environment.”) by the W3C recommends them as the ultimate test of how readable your colors are. This is not an exaggeration because some of the technical limitations of mobiles (and the environment you use them in) basically take away from you many of the advanced color options desktop displays award you with.
Image from Wikipedia
Color Depth Dictates Fewer Colors
One of the main characteristics of mobiles to take into account is their color depth. Technology is improving rapidly but still even the best models today have relatively low color depth. Low color depth, such as 8 or 16 bits means that a device is capable of displaying 256 and 65,536 shades of red, green, and blue, respectively, which is far from enough.
It is true that mobile displays are constantly increasing their color depth but there is still a lot of room for improvement. For instance, this article (though a bit old) gives an idea of what color depths some of the major brands on the market today offer. For a more detailed look at color depth, check this white paper.
Therefore, if you want to make the colors of your mobile site user-friendly, use as few colors as possible. It is better to stick to main colors and avoid the use of fancy ones because the risk of them not being displayed properly is higher. Additionally, because of the small mobile screens, you simply don’t have much space for lots of tiny squares all in different colors, which further forces you to use a palette with fewer colors.
Brightness and Contrast Settings Demand High Contrast Schemes
In addition to color depth limitations, you also need to consider brightness and contrast settings. The levels you see on specifications might sound decent but they can be misleading because they don’t take (and can’t take) into account the actual viewing environment. For instance, a very common use of a mobile is in the brightness of daylight, when the perceived brightness and contrast are much lower than the ones stated by the manufacturer. You can’t make your visitors browse your site only in the dark of the night to see it in its full glory, right?
What is more, many users keep the brightness and contrast settings low on purpose to conserve energy. All these mean that your site will be viewed with less brightness and contrast. To counterbalance, you need to use really high contrast color schemes. You can use a contrast analyzer to check how you fare.
Be Careful with Gradients and Background Images
If you use a lot of gradients in your designs (as I do), you need to be even more careful. Gradients are cool, but really only on a desktop. On a mobile, a user can see gradients even when they are not present – he or she just needs to bend the device a little, and voila, here is a gradient that you didn’t include in your design. Of course, this doesn’t mean you must kick gradients completely out of your mobile repertoire but if you minimize their use, this won’t be a mistake.
Backgrounds pose a similar problem. The same background might be perfectly legible on a desktop but on a mobile it might be impossible to read the text. It is your task to make sure this doesn’t happen.
Don’t Rely on Colors to Convey Meaning
Even with desktop design, it is not good to rely on colors to convey information – every usability expert will tell you this. However, this is true for mobile designs and even W3C has included it in its Mobile Web Best Practices.
Time to Get the Color Scheme Ready
Image by Wikipedia
When you get to the very task of choosing the color scheme for your mobile site, you need to take into account the meaning of colors and the right color combinations to use. Even if you plan to reuse your desktop color palette, it won’t hurt to see if a better alternative is available and try using a color scheme generator. These also help when you are stuck and have no idea which colors to use, or if you simply want to speed the process. You might not like every scheme the generator offers you but often the suggestions are at least decent and with some minor modifications (i.e. replace the colors in the scheme you don’t like with other colors you find more suitable), you are done.
Examples of Mobile Sites – Great, Good, Bad, and So-So
1. Weather Underground – a great site with clean design visible on any screen
2. Craigslist– boring to look at but really useful, very minimal, as the site itself, doesn’t waste my bandwidth with useless imagery.
3. Gmail – clean and easy to use.
4. Flickr – if they didn’t use the colors from the main site, the contrast could have been better but still it is OK.
5. Walmart – clean interface, though the text color is a bit light.
6. McDonald’s – the logo is rather pale, occupies a lot of space on the screen, but when you scroll down, things get better.
7. Digg – rather pale, difficult to read.
8. Bloomberg – again, could have had more contrast but not bad as a whole.
9. US magazine – the colors don’t have enough contrast, blurred and hard to read.
10. AztekWeb – gradient + low contrast + scrolling + light text on a dark background, though it probably could have been worse.
If you are familiar with color theory and if you have experience in designing desktop sites, you won’t find it difficult to come up with good color schemes for your mobile site. In fact, thanks to the specifics of mobile sites and the fact that all equal you need fewer colors, you might find it easier to design mobile color schemes than desktop ones.