Posted on January 18, 2010 - by Lisa Nalewak
This is the 2nd in a series of articles on Graphic Design specifically written for Business Professionals.
RGB color stands for “Red Green Blue”, and RGB color is used specifically for electronic display of graphics and images. All colors generated on TVs and computer screens are a result of the combination of red, blue and green light emitted by electronics inside each device.
A TV screen or computer monitor is made up of thousands of little “bulbs” or pixels that sit very close to each other, and together make up your whole screen. Every pixel has the capacity to be its own color. Every color displayed in each of these pixels is a balance of the intensity of light for each of these three colors as they overlap in the same pixel at the same time. When viewed from a distance, these differently colored pixels make up a whole picture, and allow for variations of color across the entire screen.
When graphic designers create graphics that are meant to be displayed electronically — like for web sites or PowerPoint presentations or for CDs or DVDs — they “set” the colors for the graphics they create as “RGB”. This way, the electronic device displaying the graphic knows what balance of red, green and blue light to use for each pixel that makes up the graphic. In addition, your graphic will display consistently on every RGB device.
RGB colors are defined by using specific values for each color to create all the unique colors of the spectrum. The highest value for one color is 255, which means that color is being displayed at its brightest. The lowest value for one color is 0, which means that color is essentially “turned off”. By combining different values for each of the three colors, a computer monitor or TV screen essentially mimics the entire visible spectrum.
For example, a pure, bright red color has the RGB value of 255, 0, 0. That means the red value is set at 255, the green value at 0 and the blue value at 0, or R=255, G=0, B=0. A pure bright green has the RGB value of 0, 255, 0. A pure bright blue is 0, 0, 255. Black is 0, 0, 0, or the absence of light. White is 255, 255, 255, or the inclusion of all light (I’m starting to sound like your high school physics teacher, aren’t I?). The higher the color values for each color, the lighter the shade. The lower the color values for each color, the darker the shade.
What does this mean to me?
So what things do you need to keep in mind about RGB color that’ll make your life easier when purchasing design services or artwork, or when you need to use or modify art you already have on file?
1) The vast majority of machinery used to produce printed materials does not use the RGB color format to define colors. Instead, it uses inks or combinations of inks to approximate the hues of the spectrum. As a result, RGB COLORS DO NOT MATCH THEIR EQUIVALENT PRINTED COLORS. They are two completely different ways of generating colors so the end result is different as well.
2) You can NOT use art set up for printing (ie. NOT set up in RGB color format), on an electronic device. If you’ve ever been sent a photo attached to an email that showed up as a little red X that you were unable to view, chances are the photo was not set up in RGB color, and your monitor or TV couldn’t display it because it was missing the RGB color information it needed to do so.
When you try to print RGB artwork, or convert RGB artwork to the appropriate color format for printing, you will get a color shift. That means the closest color used in printing for the RGB color you see on a screen will look different from each other when held up side by side. In some cases it’s very different (blues and purples translate the poorest from RGB to print colors). In other cases it’s not as noticeable.
You must be prepared for this color difference. I’ve had many, many customers come to me in the past who were upset with previous artists or printers, because artwork they pulled off their website or out of a PowerPoint presentation did not print out on their LaserJet or on their business cards as the same color that they saw on their screen.
This was not the designer’s fault: the designer created RGB artwork for use on the Website or inside a PowerPoint presentation, not for print. This was not the printers fault: they printed what the client gave them to print, in this case a file that was originally created in RGB to view on a screen. Ultimately, the problem arose because the art was being used in the way for which it was not created. This is why it’s extremely important that you ask your designer to create artwork specifically for the use you intend, just so you can avoid color suprises and conversion pitfalls.
How to handle RGB artwork for print
A good designer will ask you how you plan to use the art they are creating for you, and then will deliver you the art in multiple file formats and in multiple color formats that are matched as closely as possible. In this way, they assure that you have the art you need for any application, whether it’s print or electronic so you don’t experience color surprises down the road.
If you have RGB artwork that you need printed and you don’t have it in another color format specifically set up for print, a knowledgeable designer will be able to convert your RGB file to print color formats for you. How they accomplish this, and how well they accomplish this is based on the type of file you give them, and on the graphic quality of the file. Art that is still in it’s ‘source’ or ‘editable’ form is easiest to work with, and the higher the resolution quality of the artwork, the better the result. The more complex the art, and the poorer the resolution, the harder it is to achieve a good conversion result. If a file is “flattened” (meaning all the art elements are in a single layer inside the artwork and can’t be “lifted” and moved around independently of one another), the lower the quality of the result.
Ultimately, it’s up to your designer to recommend what they believe is the best way to handle an RGB-to-Print color conversion, but they can’t accomplish this until you understand why you need it done and ask that they do it for you.