Real World Computing

The Swatches panel's default library of CMYK presets is a fairly random selection, but plenty of other libraries are available via the "Open Swatch Library" command. Where presets come into their own is when there's some physical rationale for the colours included - for example, only web-safe colours, only Windows system colours, or proprietary ink-based spot colour palettes such as those supplied by Focoltone, Toyo, Trumatch and Pantone (which are all hidden away under the Load Library | Color Books submenu). Spot colour libraries are great if you have a limited two- or three-colour print budget, for ensuring a consistent house style, or for grabbing attention by stepping outside the default CMYK colour space, but don't choose spot colours solely on their inaccurate onscreen representations - you must work from a printed reference.

Good with colours

Swatch libraries simplify the process of choosing single colours, but they won't help you pick colours that work well together: for that there needs to be some underlying logic and balance at work. So how are the different colours connected to each other? With tints or shades of the same hue the connection is clear enough, but what about entirely different hues? Again, the answer lies in context, and is based on the way your brain interprets the wavelengths of light as colours. We interpret the opposite ends of our visible spectrum as being similar, so violet feels as if it has a red component: we can therefore join the ends of the rainbow into a circular "colour wheel" containing all the hues. (That's why hue is specified in 360 rather than 100 steps, each corresponding to one angular degree.) The colour wheel imposes a logic in which adjacent colours are seen as similar and "analogous", while opposite colours are seen as contrasting or "complementary".

Your task as designer is to achieve "colour harmony", by balancing variants of a single colour with both analogous and complementary hues and their corresponding variants. There's not one mixture of colours from around the wheel that will work perfectly for every job, but over the years certain "harmony rules" have become established - for example, choosing three or four equally spaced colours ("triads" and "tetrads") plus a more saturated or lighter variation of the base colour. Such underlying colour balance and tension is absolutely central to the success of a design, but computer design applications have mostly failed to provide any tools to help create, apply and control colour harmonies.

Thankfully, Adobe finally rose to the challenge in Illustrator CS3. For a start, it offers selections of working colour schemes or "colour groups" that you can access via the Swatches library panel, but more importantly, you can create your own colour groups using the entirely new Color Guide panel. The currently selected colour in the Color or Swatches panel is your base, then by using the drop-down list to its right you choose among automatically generated colour harmonies of up to six colours, based on 24 different harmony rules. Once you've selected your preferred colour group, copy it to the Swatches panel, and the Color Guide panel offers further selectable tints, mixes and variations on the group colours.

The Color Guide panel really is a massive breakthrough for designers, a great help when making fundamental colour decisions at the start of a job, but colour is such a central pillar of design that, unless you're working to a predefined house style, you're almost certain to want to tweak your original colour choices (even change them completely) as your work progresses. To be truly useful, colour groups need to be easily updatable. Moreover, as when editing individual colours, it's vital that colours already applied can be automatically updated, too, freeing you to explore creative options interactively on the design. Illustrator CS3 provides precisely this power in its Live Color capability.

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