Colour is usually the last decision made on a project and the first one the client sees. Bright and deep hues are in vogue with the design community right now, and the choice is often made by the specifier or the property owner to land a particular look. That is a legitimate goal. It is also, more often than anyone admits, the decision that quietly sets the repaint date.
Within the same product, the same environment and the same exposure, a lighter colour will always outperform a darker one. That is not a Prominent Paints opinion. It is how pigments, heat and paint films behave in South African sun, and it has consequences for the schedule, the budget and the long-term appearance of the building. This article sets out what those consequences are so colour can be specified with them in view.
Colour durability: which pigments hold and which do not
Colour durability is the coating’s resistance to changing colour or fading on exposure. Pigments differ widely in their light stability. White has the greatest resistance to UV degradation. Bright and deep hues, especially reds, oranges and yellows, are traditionally the most UV-sensitive and fade the most readily. A red front elevation and a white one, coated in the same product on the same day, will not look the same age in three years.
There is a second layer to this that rarely makes it onto a specification. Standard colours produced in the factory will by far outlast many colours tinted to a specific requirement at the point of sale. The difference is the pigment. Factory colours are built on production pigments chosen for exterior stability. Tinted colours are built from stainers, and a recipe that leans on primary, secondary or tertiary colour pigments may not withstand long exposure and can show premature fading.
The Neuklad data sheet is candid about it: premature fading can occur with dark tinted colours. That is not a flaw in the coating. It is the chemistry of the colourant, and it applies to every exterior paint on the market. The practical rule for a specifier is simple. Where a colour will sit in the sun, prefer a factory standard colour, and treat a tinted deep hue on a north or west elevation as a decision with a shorter maintenance interval attached.
Heat absorption and what it does to the substrate
Bright and deep hues have a lower Light Reflectance Value than lighter colours. They reflect less light, and they absorb more heat. On a South African north or west elevation that is not a marginal difference. A dark wall can be hot to the touch by early afternoon while a white wall next to it is merely warm.
That heat goes straight into the substrate. A warmer wall expands more during the day and contracts more at night than a cooler one, which places significantly more stress on both the coating and the plaster or masonry underneath it. Early in its life a good exterior film handles that movement. As the film ages it becomes less flexible and less able to keep up with the constant cycle. The destructive result shows up as crazing, cracking, flaking, peeling or blistering, and it shows up first on the elevations that run hottest.
The commercial translation is that bright and deep hues traditionally break down more quickly and have a shorter life expectancy to first maintenance than lighter colours in the same environment. A specification that assumes the same repaint cycle for every colour on the building is going to be wrong on the sunny side.
Hiding power and the coat count nobody prices
There is a third effect that surfaces on site rather than in the design meeting. The opacity of bright and deep hues, especially reds, oranges and yellows, can be relatively poor. To reach the required depth of colour, large quantities of colourant are added to a clear base with no opacity or an extra bright base with very low opacity. Little or no white pigment, titanium dioxide, is present, so the hiding power of the colour relies almost entirely on the relatively weak opacity of the colourant pigments.
In practice that means more coats to reach a uniform finish, and more coats means more labour and more material than the tender allowed for. It also means the applicator is tempted to stretch each coat, which is precisely the wrong response. Overall coating performance depends on film thickness. The film is what gives the coating longevity and stops it disintegrating off the surface under constant exposure.
Prominent Paints Neuklad is designed to build around 75 microns of dry film per coat, roughly 150 microns across the standard two-coat system. Where a strong tinted colour needs an extra coat to hide, price that coat and put it on. Do not recover the coverage by thinning the film. A wet film gauge on site is the cheapest quality control on the project.
Specifying colour by elevation
None of this argues against colour. It argues for specifying it by exposure rather than by mood board. The north and west elevations carry the heaviest UV load and run hottest. The south elevation may barely see direct sun in winter. Treating them as one surface with one colour and one maintenance cycle is where the trouble starts.
A workable approach is to keep the exposed elevations in factory standard colours, and lighter within that, and to place bold, deep or tinted colours on sheltered planes, entrance features, elements under an overhang or interior-facing courtyards where they will hold far longer. Where the client insists on a strong colour on an exposed face, the specification should say so, carry the extra coat and carry a shorter maintenance interval, so nobody is surprised later.
Preparation still decides whether any of it works. If the existing surface is chalking, the loose material has to come off and the surface sealed before the new system goes on; new cement plaster needs its primer or sealer before top coats. Neuklad Alkali Resistant Sealer is the primer in the Neuklad system for exactly that purpose. A colour argument on a badly prepared wall is academic.
Why this belongs in the tender, not the defects list
The reason to write colour into the specification with its performance consequences attached is commercial. Uneven fading on the street-facing elevation is read by the client as a failed paint job, not as a pigment characteristic they chose. Extra coats discovered on site become a variation claim or a squeezed margin. A repaint cycle that arrives early on one elevation becomes a warranty conversation.
All three are avoidable if the decision is made openly at specification stage. State which elevations are exposed. State that lighter, factory standard colours are specified there for durability. State the coat count for any strong tinted colour and the film build per coat. State that the maintenance interval differs by elevation. The client keeps their design intent, the contractor prices the job correctly, and the building looks like the same colour on every side for longer.
The Prominent Paints technical team reviews exterior specifications with contractors and specifiers under the Professional Pact, including colour selection by exposure, system and film build. It is a short conversation before pricing that removes a long one afterwards.
Frequently asked questions
Why does a lighter colour last longer outdoors than a darker one in the same paint?
Two reasons that compound each other. Lighter pigments, and white in particular, are more resistant to UV degradation, so they fade more slowly. Lighter colours also have a higher Light Reflectance Value, so they absorb less heat, which means the substrate expands and contracts less each day and the film is under less stress. Within the same product and exposure, the lighter colour will outperform the darker one on both counts.
Which colours are most likely to fade on a South African exterior?
Bright and deep hues are the most UV-sensitive, with reds, oranges and yellows traditionally the first to fade. Tinted deep colours built from stainers are more vulnerable than factory standard colours, because the colourant pigments may not withstand long exposure. The Neuklad data sheet notes that premature fading can occur with dark tinted colours. On a north or west elevation these effects are strongest.
Is a factory standard colour really more durable than a tinted match?
Yes, as a general rule. Factory colours are produced with pigments selected for exterior stability, while tinted colours are made from stainers whose primary, secondary and tertiary pigments may not hold up to long exposure. Where an exposed elevation must carry a deep colour, a factory standard colour is the lower-risk choice. Where a tinted match is unavoidable, specify it with a shorter maintenance interval.
Why do bright tinted colours need more coats?
Because the base they are tinted into has little or no white pigment, so the colour’s hiding power depends on the colourants alone, which have relatively poor opacity. More coats are needed to reach a uniform finish. The right response is to specify and price the extra coat, not to spread each coat thinner. Film thickness is what delivers the coating’s longevity, and Neuklad is designed for around 75 microns of dry film per coat.
How should I write colour into an exterior specification?
Specify by elevation. Identify the north and west faces as high UV load and keep them in lighter, factory standard colours. Place bold or tinted colours on sheltered planes and features. State the coat count and dry film build for every colour, and note that the maintenance interval differs by elevation. That way the design intent, the pricing and the client’s expectations all match.
Does colour choice affect the warranty?
Preparation, application and colour all form part of the conditions under which an exterior system performs, and the Neuklad paint film warranty applies to white and approved colours on correctly primed exterior facades. Before quoting a strong or tinted colour on an exposed elevation, check the current warranty terms with the Prominent Paints technical team so the client understands what is covered. It is far easier to have that conversation before the tender than after the first summer.
Specify the colour and its consequences together
Colour will always be chosen for how it looks. The specifier’s job is to make sure it is also chosen for where it will sit and how long it has to look that way. Lighter and factory standard on the exposed faces, bold where it is sheltered, the full film on every coat, and a maintenance interval that is honest about the difference.
If you are scoping exterior work for the summer season, the Prominent Paints technical team will review the colour and coating specification with you under the Professional Pact. Find out more at www.prominentpaints.co.za/professional.