Colour Spaces Explained: sRGB, Adobe RGB and When to Use Each

Here’s a thing that has annoyed every photographer who has ever lived.

You edit a photo. The colour is superb. You are, briefly, magnificent. You put it on the web and it comes out looking like somebody left it in the sun for a fortnight. Grey. Flat. Sad.

You haven’t done anything wrong. You’ve just sent a photo somewhere that can’t show all its colours.

What a colour space actually is

Think of a box of crayons.

A colour space is the size of the box. A big box has more colours in it. A small box has fewer. The photo is the drawing, and the box is how many colours you were allowed to use.

That’s genuinely it. The rest is just knowing which box to use when.

The four boxes you’ll meet

sRGB is the small one. It’s also the one the whole internet agreed to use, so every phone, browser and website understands it. Small box, but everyone speaks it.

Adobe RGB is bigger. More greens and cyans especially. Print companies like it because it covers most of what their ink can do.

ProPhoto RGB is enormous — bigger than your eyes can actually see, which is a strange thought. Useful while you’re editing, useless for showing anyone anything.

CMYK is the odd one out. It’s not light, it’s ink: cyan, magenta, yellow and black, layered up on paper. Instead of adding light it takes it away from the white of the page.

The rule, in one line

Edit big, export small.

Work in a big box while you’re editing so you’ve got room to push colour about. Then, right at the end, put it in the box that suits where it’s going.

• Going online? sRGB. Always. No exceptions worth caring about.
• Going to a printer? Ask them. Most want either Adobe RGB or sRGB, and they’d much rather tell you than fix it.

One thing that catches everybody

You can go from a big box to a small one. You cannot go back.

Save something as sRGB and the extra colours aren’t hiding — they’re gone. So if you shoot JPEG and you’re not sure what the photo is for yet, shoot the biggest space your camera offers. You can always come down later.

If you shoot RAW, relax. A RAW file has no colour space at all until you edit it. That in-camera setting only changes the little preview on the back. This is one of the quiet reasons RAW is worth the bother.

How to actually change it

In Photoshop: Edit, then Convert to Profile.

Use Convert to Profile, not Assign Profile. Convert translates the colours properly. Assign just relabels them and shifts everything, and then you’re squinting at your screen wondering why the sky went odd.

In Lightroom, it’s part of exporting. Pick sRGB in the export box for anything going online.

So

Big box while you work. Small box when you’re done. sRGB for the internet, ask your printer for paper.

Do that and your photos will stop losing their colour on the way out of the door. Which is, I think you’ll agree, a low bar we should all be clearing.