Saturday 21 March 2015

What colour is a crocodile?

 
Sobek, looking very RGB.
  So – what colour is a crocodile?  You know what a crocodile is don’t you?  A crocodile – sort of slung low to the ground, crawling on four legs –tail dragging behind.  Long snouty head, jaw full of teeth – twist you in half in a second.  That crocodile. 

If I asked what colour it is, you would probably say, a kind of dirty brown.  I’d agree, there may be a number of colours that make up that dirty brown (remember when you were a little kid in class, you mixed all the colours in the paint box together to see what colour they would make?  Brown – what a disappointment,) but generally its an olive greenish brown.

Go to child’s storybook though, and invariably a crocodile will be green.  In fact, all lizards and amphibians will be green regardless of whether they are or not.  It’s a convention of such material, probably to make sure the book is bright and cheerful for children, but also because it’s easier and cheaper to print one solid primary colour.And that brings me to the problems of print.  I can’t say I know much about this as I was never trained in graphic art and therefore never learnt much about how print works.  But I know that printers will print your art using the CMYK colour process, which stands for Cyan, Magenta, Yellow and Key – Key being black.

 
Example of colour shift on green crocodile.  With hands!

What it means is that digitally you want to create your work in colours that most closely approximate the real world, or at least which look bright and clean – pleasing to the eye, and so use the digital RGB (Red, Blue Green) to produce your image.  This is fine if you just want it to stay on a computer screen, (although there’s often a certain discrepancy in the way different screens handle colours) but if it’s going to be printed anywhere you’re probably going to have to deal with colour shift.

I’ve not really thought about this much and I think it’s about time I started.  For all those bright clean colours I like will become a little bit duller when printed in CMYK.  So that crocodile in the children’s book you just produced will be a darker green than you want.  Ironically it will be a tiny little bit closer to the way crocodiles actually look.  Does that mean CMYK is a good thing after all?With a certain amount of experiment I’ve come to realise that I can live with most of the colour shift that will result from a conversion between RGB and CMYK.  The reddish orange and yellows look okay, and dark reds still work pretty well.  The bright greens darken a little, but are still acceptable.  The one colour that is really effected by CMYK conversion is blue.


And that’s a shame, as I always liked a nice strong sapphire blue.  When this is converted from RGB to CMYK the brightness disappears and you are left with a kind of bluish slate grey.  It actually doesn’t look that bad, when with the right combination of other colours, it just means you have to be aware of the fact of the change and design accordingly.


But, for instance, this design of Bast in black with a blue outline would mean that the outline now almost disappears because it’s gone so dark.  I’ve spent a little time re-colouring some of my designs because of this problem, concentrating on the red yellow side of things because I think there’s less shift.

RGB above, CMYK below. 
In this example above, the comparison shows RGB on the top, CMYK on the bottom, and its obvious the reddish colours hardly seem to be effected at all.  At the left the red outline still looks the same although Anubis’s green vase has dulled a little.  The lettering has gone that slate grey I mentioned but the yellow has been unaffected.  On the right, I must admit the bright sapphire blue I chose doesn’t go with that type of orange, it causes the blue to almost fluoresce.  The darkening of the blue caused by the conversion to CMYK has actually improved it slightly, and I think I would have darkened that blue anyway.  So, the design on my screen looks like the top images, and what you get when its printed are the bottom images.

In most respects the conversion doesn’t cause too much harm, I will just have to remember even though it makes me a little blue – no more blue.


4 comments:

  1. Doesn't the distance you are from the croc have a bearing on what colour it is? For example, if you are too close, it would be tooth colour ... :-)

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  2. Right, as always, Madwippit. Tooth is a major part of croc design.
    Bro - really enjoyed this. It taught me stuff.

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  3. You have a point madwippitt, (as do the crocodiles teeth) but I think we might define the colour of crocodile teeth when seen close up as red. Glad you like it Sue, but neither of you spotted the deliberate mistake - where I try to bamboozle you by alternating CMYK with CYMK. It was completely intentional of course.

    Now I'll have to go back in and correct it : (

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