Why we can’t choose your colour for you…

Colour can be the hardest part of the building process!  The overwhelming confusion (and exhaustion) on the faces of customers bringing their array of potential choices into store affirms this regularly!

Sometimes clients will request that we just choose a ‘grey’ or a ‘white’ or a ‘stone-colour’ on their behalf to mix up.  We love going above and beyond for our customers but, No thank you!  This responsibility is about as appealing (and irrational) as choosing a favourite child.

We specialise in colour matching.  We see SO many colours everyday.  Our expertise is in tinting accuracy and the science and application behind the tint-able products themselves.  We can supply you with beautiful aesthetic finishes, however, choosing from the copious variations of ‘grey’ out there without being exposed to the factors that influence colour on your particular site is a little risky!

On a level, far too deep for this article, science accepts that people perceive colour differently by the constitution of their eyes, the context and surroundings and even subjective emotional responses to light, shade and hues.  You don’t want to know how we feel about a colour, and we cannot choose one on your behalf, but we can offer considerations in choosing colour for external render and texture finishes.

The appearance of a colour is manipulated by a few fundamental factors:


Compositions of products with sand, aggregates and other minerals affect the appearance of colour. Coloured decorative textures may appear different than the same colour in a flat paint.  The shaped nature of even the finest sand-based material will adopt shadows across the surface that can cause a colour to appear darker across an exterior broad wall.  For this reason many consider a shade 25% or 50% lighter of their chosen colour.


The natural ingredients selected to enhance the aesthetic of a texture product also interact with colour differently.  For example, the ‘sparkle’ ingredient of some texture products are enhanced with darker hues and disguised more in lighter colours.


Colours can look different at various times of day, by weather conditions, in artificial lighting and will definitely be different viewed inside compared to outside. Light also reflects differently over different surfaces and between different sheen levels of surfaces.  The variation in colour at a certain time of day on the far end of the house may be quite insignificant in the whole scheme of things.  A hasty dismissal of your favourite choice that sends you back to the drawing board might have been avoided with different perspectives.


Choosing colours from brochures, chips, paper swatches and electronic images or on different types of devices will not be true reflections of a colour, especially over a rendered and/or textured surface.

LRV – Light Reflective Value

A light Reflective Value is a measurement of how much light a colour reflects or absorbs.  The LRV scale ranges from 0% to 100%.  The lowest values represents very dark through to a 100% absolute reflecting white.  Low LRV colours will absorb heat and therefore the background surface must be a consideration when choosing colour.  Truly heat absorbing colours should be avoided over fibre cement sheeting and expanded polystyrene products to meet the performance and insulation value of the full system.  In contrast light colours in very fine products can be more unforgiving of an uneven background surface in glancing light.


Neutral colours are a great choice as the primary colour, however even neutral colours have underlying tones of green, blue, red or yellow.  Light can wash out the chosen neutral and bring out these tones which will impact on the appearance of the colour.  A colour you thought was grey, may appear brown as light plays with an underlying red hue on a sun-bathed main wall.  Often it is better to choose a neutral that has more depth to the colour to avoid picking up on these tones that form part of that colour base.  The underlying tone is often more important in choosing the right complementary adjacent, accent or feature colours.  A feature that throws pink in the sun may not be appealing with the green coming our of the grey primary colour palette.


For a superior finish and to support true colour consistency and appearance it is a good idea to prime the wall (often tinted to the same colour) prior to texture coats, protective coatings or paint.  Unless specified otherwise this assists to even out the surface and close up the coloured finish evenly.


The explanation of factors to consider doesn’t necessarily  make the process of choosing colour any easier but provides some insight into getting the most out of the appearance of your preferred colour choices in render and texture systems.

ALWAYS get a sample of your potential colour choices in the product you have chosen as a finish.  RTP’s colour sample service is an efficient and effective way of confirming your preferences.  Get your applicator to apply the sample to a good size board so you can view the colour in various lights, times of day, and various points and aspects around the project.



We can offer further tips in how to go about the process of choosing colour, but that ‘sandstone colour’ is for you to enjoy selecting.