Yes. Which is to say, both. Or either. Bear with me, it’s really not that confusing. All the photos on iStock are RGB, but vector illustrations can be created in either color space. When you purchase a vector file from iStock, your download will always contain 2 files: The editable-in-a-vector-drawingprogram EPS file, plus a high-resolution JPEG file. The folder you get will look something like the image on the right:

How do I know which one I’m getting in my download?

The JPEG will always be in RGB, but the EPS could be either.

If you open the file in Illustrator, the surefire way to tell is to look at the file’s title bar, which will show the color space, among other information.

It depends on what you use it for. Simply put, CMYK is for printing, RGB is for viewing on screen in Web pages or cell phone interfaces, for example. The difference is ink (CMYK) vs. light (RGB). For a more detailed discussion of the two color spaces, see this article.

By all means! If the EPS file you download is in CMYK, you’re pretty much good to go with your printer (See this article for more information on preparing files for print). You can use the provided JPEG file, which is always RGB, for your Web page.

If the EPS file is RGB, however, it might get a little tricky. Let’s have a closer look at an RGB vector file:

The rich gradient in the sphere contains a pure blue, which is why it looks brilliant on your screen. You’ll notice, however, there’s a little yellow warning symbol in Illustrator’s Color panel. This is telling you that the color is out of “gamut,” that is, beyond what can be printed with CMYK inks.

If you don’t intend to print, no worries. The file will look pretty much as it does in Illustrator or in the RGB JPEG included in the download. If you click the triangle to correct the out-of-gamut color to a printable color, you may be in for a surprise.

That brilliant, pure blue is now quite a bit more subdued. So use the RGB on your Web page, but be prepared for a possible color shift when printing.

If you haven’t downloaded the file yet, you can look for some clues in the preview on the file closeup page. If there are bright blues in the image, as above, that’s usually a giveaway that the file is RGB. Bright greens and really hot reds can also indicate an RGB file. To be sure, contact the artist via sitemail and ask first. And artists, how about putting that information in the file description to help out the designers, okay?

Absolutely. You can easily move elements from one file to another. Again, if you plan to print, make the destination file CMYK, and if your masterpiece will only appear on the Web, use RGB. Here’s an example of what can happen when dragging objects between files.

On the left is that same bright blue in an RGB file. When an object filled with that color is dragged to a new CMYK file, the ink breakdown does its best to approximate the color.

Going the other direction, from RGB to CMYK, will also result in some funky numbers on the color sliders, but the color you see won’t shift.

It’s personal preference, really. Some people find it easier to mix color swatches in CMYK; others get a headache when working with RGB. It all depends on how your brain is wired. Do keep the designer in mind, and make the most versatile files you can. And as mentioned before, it wouldn’t hurt to indicate the color space in your file info box. RGB and CMYK —can’t we all just get along?