I found some colors on the web that I'd like to use in my print brochure. What's the best way to find the CMYK equivalent of a HTML color?
Your best option is probably to talk to your printer and borrow their CMYK or spot colour Pantone® book. There’s just no quick or reliable way to convert a colour you see on screen to a CMYK or spot colour.
The Pentone books are pretty expensive, so borrowing is a good idea (or visit your printer, if you can).
If you can’t do that, then another option is to find something (anything, really) that matches the colour you like, and ask the printer to do their best to match it.
And, if you can’t do that… there are some obvious choices for strong Pantone / CMYK colours, if you want bright red, bright sky blue etc.
This may help:
Since I can't comment yet, I'll put this in an answer.
I usually use this site: Encycolorpedia
Just paste in the HEX-code and they'll give you more info on the color than you'd ever want or need.
Be aware though that color conversion isn't always straightforward, as has been said before.
My routine (as a print and screen designer 20 years working in both directions). Web to Print: use a Mac with a decent monitor * so that you can judge the colour effectively / screen grab the web page / if you haven't built the page yet screen grab the HTML colour palette in your editor / open the grab in Photoshop (it will now be RGB) / sample the colour / go to colour picker - it will give you the nearest RGB / WEB and CMYK value. Finally check the CMYK value against a Pantone and / or Process swatch book and adjust to the closest you can get. This is critical as clearly you are trying to convert from colour made by light to colour made by ink on paper.
Note: printers tend to default to the quickest solution (CMYK) and you will not get every colour out of this (Cyan, Magenta, Yellow, Black combined) Printers can use spot colours (an independent colour pre-mixed for difficult tones such as bright orange, metallics, luminous inks etc which is where the Pantone range comes in as noted by Marc above. This will cost more and take longer though.
Note: I was given my first Pantone book FOC by the printer I was supplying with artwork. I later invested in a full set for my professional development - I have used these every week since. If you are serious about print and colour then get a set of Pantone books. One of the main ones I use is the solid to process which allows me to avoid many (expensive) Pantone colours in favour of a CMYK alternative. If I do this at the design concept stage I can save myself a good deal of pain later on. Hint, don't EVER choose Reflex Blue. You have been warned.
- this is for quality control andnot a Mac v Windows argument. Mac's represent and work with colour better in my experience since Apple provide hardware and software together (i.e. the OS and a utility called Coloursynq). Also its likely that professional printing pre-press operators will be on Macs.
Good luck with your work.