Pro tricks for mastering colour
The Professional Photoshop Book 17
PRE-DETERMINING THE COLOURS THAT CAN BE USED IN YOUR
WORK HAS REAL POWER, AS JON WESTWOOD EXPLAINSUNDERSTAND ICC
ESTABLISHING GAMUTS01
CONSTRUCT CONFINES
“When painting with a gamut,” says Jon
Westwood (www.jonwestwood.ca), “whatever
colours are established are the ones that will
define the colours in the piece. This is an extreme
example of how the confines of a gamut can
affect the colours in a piece. Value can be
interpreted however you want, but the idea is to
keep all colours in the composition within what’s
given in that triadic area.”02
SHRINK YOUR CHOICES
Here, “the gamut is rotated and kept the
same size and shape. It’s closer to what we want,
but there still isn’t enough restriction in our colour
choices. Let’s shrink it even more.”03
BREAK YOUR OWN RULES
This is the final image and the gamut used to define the piece. Westwood explains that “the
colours are much more muted and controlled and most of the variation is interpreted in value rather
than saturation. There are a few areas where some liberties are taken outside of the gamut, like on the
terminator of the mountain’s shadow or the vibrant rock on the far left, but the idea is to keep the
general image contained, which will bring out those features even more.”Colour management expert Paul Sherfield (www.
missinghorsecons.co.uk) explains that there are
“around seven differing types of ICC profiles.” ICC is the
International Color Consortium, an organisation set up
to look at specification for managing digital colour, and
an ICC profile “gives colour meaning to images when
used by software that is ICC aware.”
For general use, Sherfield explains, most designers
only “need to look at RGB and CMYK profiles. An RGB
profile in an image is usually defined by the creator. The
de facto ‘standard’ for professional photography is a
profile called AdobeRGB1998.”
CMYK profiles have a different purpose. “In colour
management speak,” explains Sherfield, “they are
what is termed device dependent. This means each
CMYK profile is added at a defined way of printing. It
describes the printing method, paper stock and the
inks or toners used.” So if you’re converting images to
CMYK for print it’s important to know the printing
method and paper to be used. Sherfield notes: “The
‘default’ CMYK setting is wrong for the European
market, and is not even current for the US market.”
Lab colour is something that many professional
Photoshop-using artists never have to think about, but
Sherfield explains that it is “a colour gamut or colour
space that models human colour perception. It is
modelled in the colour management system’s
software and as the ‘connection’ space used when
converting from one profile to another. So when ‘Mode’
or ‘Convert to Profile’ is used the image with its profile
describing its colours is translated into the Lab colour
space, then using the chosen output profile, converted
from Lab to this new colour space and profile.”DON’T LIMIT YOURSELF
“This may seem obvious to experienced Photoshop
users,” weighs in Aaron Campbell (www.
aaroncampbell.ca), “but many people who are new
to Photoshop feel they need to always design in
CMYK if they intend to print, which severely limits the
amount of colour you can use in your image.
Designing in RGB can allow you to have tons of
variety in colour, so when you need to print it, all you
have to do is adjust the colours in a flattened CMYK
image using tools such as Replace Color, Hue/
Saturation, Channels and adjustment layers... It is
also good to keep in mind what colours you’re using;
bright colours such as neon green (#a2fe1e) or bright
magenta (#f75ddf) will not properly display when
printed, but display beautifully on monitors.”© Jon Westwood© Aaron Campbell016-027 Colour Feature.indd 17 06/10/2015 16: