Colour in Drawings & Presentation

The first job of colour on a drawing is to establish order - to tell the eye what matters most, what matters next, and what is merely context. This is the same figure-and-ground thinking you learned for interiors, turned onto the page. The subject of the drawing should be the most saturated, most contrasting, most present thing on it; everything else should quiet down in proportion to its importance.

The classic failure is the uniform coloured plan: every room a different bright fill, all at the same saturation, a legend of a dozen equal colours. Because nothing is quieter than anything else, the drawing has no subject - the eye bounces and gives up. Compare it with a plan that uses colour with restraint: the walls sit as a quiet dark poche, the general rooms are near-neutral, the circulation is a single soft tint that reads as a connected system, and the one space the drawing is about is the only saturated colour on the sheet. Now the eye lands exactly where you want, and the plan explains itself in a second. The figure shows this move - one accent for the key space, a tint for circulation, quiet fills for the rest, and heavy poche for the walls.

Value does most of this work, not hue. If you desaturate your drawing to greyscale and the hierarchy still reads - subject dark and clear, background pale - the colour is doing its job; if everything turns into the same mid-grey mush, you have a value problem no amount of pretty hue will fix. This is why the black-and-white check from Lesson 0.1 belongs on every board: squint, or desaturate, and see whether the structure survives.

A useful discipline is to decide the hierarchy before you open the colour palette. Rank the elements: what is the one thing this drawing must say, what supports it, what is context. Then assign colour and contrast to match that ranking - strongest to the subject, quietest to the context. Colour follows the argument; it does not invent one.

The second job of colour is to group - to say 'these things are the same kind of thing'. A diagram that colours all the public spaces one hue, all the private spaces another, and all the circulation a third turns a complicated plan into a legible argument about how the building works. This is colour as a code, and codes only work if they are kept.

Consistency is everything here, and it is where most student sets fall apart. If green means 'circulation' on the ground-floor plan, it must mean circulation on every plan, in the section, in the diagrams and in the legend - not 'landscape' three sheets later. The moment a colour means two things, the code is broken and the reader has to re-learn it on every sheet, which is exhausting and undermines trust in the whole set. Build a small, fixed key for the project - a handful of meanings, each with one colour - and apply it everywhere without exception.

Keep the code small. The human eye reliably distinguishes only a limited number of categorical colours at a glance - realistically five to seven, fewer at small sizes or on a projector. If your diagram needs fifteen categories, colour is the wrong tool for some of them; combine colour with pattern, label or grouping instead. A common, honest move is to use colour for the few categories that matter most and leave the rest neutral, rather than forcing a distinct hue onto every item and creating a code no one can hold in their head.

Choose the coding colours to be distinguishable, not merely different. Colours that differ in hue but sit at the same value can be hard to tell apart, especially when small, printed cheaply, or seen by a colour-blind viewer. Spreading your code across value as well as hue - a dark one, a mid one, a light one - makes it far more robust. And where a colour already carries a strong convention in the drawing's world (blue for water, green for planting, red for fire routes), respect it; fighting a convention just to be original costs the reader.

The third job is the one most often forgotten under studio pressure: the drawing has to be readable, by everyone, on the actual surface it will be seen. A board is not judged on your calibrated laptop in a dark room; it is judged printed at A1 under fluorescent light, or projected through a tired bulb onto a grey screen, or opened as a PDF on someone's phone. Colour that is legible on your screen can collapse in all three.

The workhorse is value contrast. Text, labels and thin lines read because they differ in lightness from their background - not because they differ in hue. Coloured text on a coloured field of similar value is a classic legibility killer: a mid-blue label on a mid-green fill may be perfectly distinct in hue and completely illegible in practice, because the eye resolves fine detail mostly through value. The figure shows the ladder - dark-on-light reads at a glance; mid-on-mid strains even when the hues are clearly different. The habit from Module 8 applies directly: for anything that must be read, check luminance contrast, not just 'do these look different'.

Never let colour be the only carrier of information. Roughly one in twelve men has some colour-vision deficiency, and a projector or a bad print flattens colour for everyone. So a red 'proposed' and a green 'existing' that rely purely on hue will fail for a meaningful share of your audience; add a label, a line-weight difference, a hatch or a shape so the meaning survives without colour. This is not only accessibility box-ticking - a drawing that reads in greyscale reads better for everyone.

Finally, respect the medium and the ground. On a white board, saturated colours pop but tire the eye if overused; a mostly-neutral sheet with a few deliberate colours reads as more confident and more professional than a saturated patchwork. On a dark presentation background, the same colours behave differently and often need lightening. And always, always test on the real output - print the A1, project the slide, open the PDF on a phone - before you commit. The colour you approve must be the colour the audience gets.

Hierarchy, grouping and legibility are not three separate exercises; on a real drawing set they are one system, decided once and applied throughout. The mark of a professional set is that its colour feels inevitable - restrained, consistent and quietly purposeful - rather than decorated sheet by sheet.

Start the set by writing a tiny colour brief, exactly as you would a brand-colour sheet: the project's coding colours and their fixed meanings, the accent reserved for the subject of each drawing, the neutral family for context, and the rule that value carries the hierarchy. Half a page, agreed at the start, saves a set from the slow drift into chaos where sheet 12 has invented three new meanings for blue.

Restraint is the recurring theme. A board does not become more sophisticated as you add colours; it becomes more sophisticated as each colour earns its place. The most persuasive presentation drawings in practice tend to be mostly quiet - a controlled neutral field, careful value structure, and colour spent deliberately on the two or three things that carry the argument. This reads as confidence. A saturated everything reads as a student who has not yet decided what the drawing is about.

Worked example: a competition board for a community library. The team fixes three coding colours - a warm ochre for public reading spaces, a muted teal for shared community rooms, a soft grey-green for service - and reserves one saturated indigo purely for the central hall, the idea the whole scheme turns on. Walls stay dark poche, context stays near-neutral, all labels are dark-on-light for legibility, and every diagram carries a hatch as well as a colour so it survives a bad projector. The board is calm, the eye goes straight to the hall, and a stranger understands the building in ten seconds - which is the entire point of colouring a drawing at all.