GRP colour guide

Choose GRP colours for safety, stock availability and site fit.

Colour is not just cosmetic. In GRP grating, profiles, handrails and stair products it affects visibility, contrast, long-term appearance, heat exposure and how easily a project can be supplied.

Common colour routes

Most GRP colour decisions start with practical questions: what is stocked, what needs contrast, what will look right on site, and whether colour consistency matters across multiple product families.

Green

Common industrial GRP route for grating, platforms, wastewater, utilities and outdoor access.

Grey

Neutral finish for plant rooms, rooftops, walkways and projects where a quieter look is preferred.

Yellow

Used for nosings, edges, hazards, steps and routes where high contrast helps users notice changes.

Black or dark grey

Useful where visual restraint matters, subject to surface temperature, stock and product availability.

How colour affects specification

Decision	Why it matters	Practical GRP Express route
Stock colour	Standard colours are faster and more cost-effective than special colour routes.	Check product category availability before building the whole project around a colour.
Contrast	Edges, stair nosings, access changes and trip points often need visibility, not subtlety.	Use yellow or contrasting nosings where the access route needs to stand out.
Batch variation	Composite colours can vary by product type, batch, resin and surface finish.	Ask for samples where appearance or colour matching is critical.
Heat and exposure	Darker colours can absorb more heat in direct sun and may show dust differently.	Consider environment, cleaning regime and user contact before specifying dark finishes.
Cross-product consistency	Grating, profiles, handrails and stair products may not all share the same stock palette.	Send the whole product mix early so colour expectations can be checked together.

Colour by application

A good colour decision supports the job the product has to do.

Industrial access

Green or grey grating with yellow stair nosings is a familiar route for many plant rooms, water sites and maintenance areas.

View grating routes

Public or mixed-use routes

Colour and contrast should help people understand edges, steps, level changes and safe access paths.

View mini mesh

Architectural or customer-facing areas

Grey, black or darker routes can work well, but samples and stock checks become more important.

Ask technical support

Electrical and data sites

Colours often need to work with plant-room standards, identification routes and non-conductive access needs.

View data centres

Stairs and edges

Nosing contrast is one of the most useful colour choices on stair routes and maintenance access.

View stair products

Cut-to-size projects

Confirm colour before cutting, drilling or preparing panels so replacements and repeated shapes stay consistent.

Plan cut-to-size

Need colour consistency across an order?

Send the product mix, quantities, preferred colour, contrast requirements and any project standard. We can check what is realistic before the order is cut or packed.

Ask technical support Back to Technical Hub

Colour is a specification item, not only a visual choice

GRP colour is commonly produced through pigmentation of the resin and may also be affected by the surface veil, finish and production batch. A named colour or RAL reference should be treated as a target unless an exact tolerance and measurement method are agreed.

Before approval

Request a current physical sample from the intended product and resin system.
View it under the project’s relevant daylight and artificial lighting.
Agree acceptable colour variation, gloss and surface texture.

Across batches

Order visible adjacent components together where colour uniformity is critical.
Record batch identity for phased work and replacement stock.
Do not judge exact shade from a screen or printed chart.

In service

UV exposure, cleaning chemicals, temperature and abrasion can change appearance over time.
Confirm the resin/veil system for the exposure, not colour alone.
Allow for weathering when matching new components to aged installations.

Engineering note: Colour does not establish fire, electrical, slip, structural or chemical performance. Specify and verify those requirements independently for the exact product.

Colour selection and product routes

Use colour guidance with the exact product family and variation data. RAL references, stocked colours and resin requirements should be checked before matching a site standard.