Outdoor Stone Colour Enhancer That Won't Yellow

Stone outdoors takes a beating in India, which is why choosing the right outdoor stone colour enhancer matters. Fierce sun, then monsoon rain, then dust. Sandstone paving, slate cladding, granite steps and concrete pavers slowly lose their depth of colour and start to look chalky and pale.

A colour enhancer brings back that depth of colour. The worry is that some enhancers form a film that yellows in the sun or goes on patchy. This guide is for homeowners, landscape contractors and architects working on terraces, poolsides, garden paths and facades. We use Faber Croma-S, a solvent-based colour enhancer designed to stay stable in sunlight.

Outdoor stone colour enhancer: Faber Croma-S

What Faber Croma-S is (and when to use it)

Faber Croma-S is a solvent-based, stain-resistant, colour-enhancing treatment with a matt finish for absorbent materials. Compared with traditional colour enhancers, it penetrates deep into the material and does not form a film on the surface. It is easy to apply, which reduces the risk of an uneven result.

It is UV-resistant and the data sheet states it does not yellow over time when exposed to direct sunlight. That is what makes it a good fit for sun-exposed stone. It is suitable indoors and outdoors.

Suitable surfaces listed include sandstone, slate, granite, limestone, marble, travertine, quartzite, porphyry, basaltina (lava stone), molten basalt, tufo, terracotta, concrete, concrete tiles, reconstructed stone and marble or quartz agglomerates.

When not to use it: the data sheet says it is not suitable for polished surfaces. Don’t apply on wet or humid stone, on overheated surfaces, or on freshly laid stone before the adhesive and grout have cured.

What you need

Faber Croma-S (1 litre or 5 litre bottle)
Lambswool applicator, roller or cloth
For large areas: single-disc machine with a white pad or wool pad
For small areas: hand polisher, or wool or cotton cloths
Masking tape and sheeting for walls, frames and plants
White spirit for cleaning tools
Solvent-resistant gloves, eye protection and a suitable mask

Step-by-step: How to use an outdoor stone colour enhancer

Clean and dry. Remove all dust and dirt. The stone must be completely dry; never apply on wet or humid surfaces. After monsoon showers, give it time to dry right through.
Pick the right time. Surface temperature should be between +5 and +40°C. Avoid stone that is overheated by midday sun; early morning or late afternoon is usually easier on terraces.
Protect surroundings. Mask anything not being treated: walls, window frames, metal, plants.
Test patch. Treat an unexposed area or spare piece and judge the colour once dry.
Apply a thin, even coat. Use a lambswool applicator, roller or cloth and cover the whole surface uniformly. Coverage is about 15 to 20 m² per litre.
Even out after 5 to 10 minutes. Before the product is absorbed, spread any residues evenly for a seamless result.
Second coat on very absorbent stone. If needed, apply a second coat 2 to 3 hours after the first.
Remove residues on compact stone. On denser, less absorbent stone, remove all residues to avoid an oily patina. On large areas do this after 20 to 30 minutes with a single-disc machine and white or wool pad; on small areas use a hand polisher or a wool or cotton cloth. For maximum colour you can wait up to 40 to 60 minutes before removing residues, but removal may take more time.
Let it dry and reopen. It dries in 1 to 2 hours. Resume use after 4 to 6 hours. Clean tools with white spirit.

Tips and common mistakes

Never leave residue on dense stone. The data sheet warns that residues left on compact, less absorbent stone can create an oily patina.
Don’t use it on polished granite or marble. For compact, low-absorbing and polished stone, look at Faber Packed-S instead.
If the stone already has a water-repellent sealer, wait until that is completely dry before applying Faber Croma-S.
Watch the weather. Choose a dry spell before or after the monsoon so the stone is dry and rain won’t hit it during the 4 to 6 hours before use.
For care afterwards the data sheet suggests Faber Neugel or Faber Algafloor for daily cleaning and FABER 30 or Faber Deterfug for heavy-duty cleaning.

Safety and storage

Faber Croma-S is solvent-based with a flash point below 21°C, so treat it as highly flammable. No smoking, flames or sparks nearby.
Use suitable PPE and follow the product safety data sheet. Work with good ventilation and avoid breathing vapours.
Keep children and pets away until the surface is dry.
Store tightly closed in a cool, dry place. Shelf life is 12 months in the original sealed packaging.

Frequently asked questions

Will Faber Croma-S make my stone shiny?

No. It gives a matt finish while deepening the colour, and it does not form a surface film.

Does Faber Croma-S yellow in the sun?

According to the data sheet it is UV-resistant and does not yellow over time when exposed to direct sunlight, which is why it suits outdoor stone.

How long before I can walk on the treated stone?

It dries within 1 to 2 hours, and the data sheet says you can resume use of the surface after 4 to 6 hours.

Need help?

Buy Faber Croma-S, a UV-resistant outdoor stone colour enhancer, from Flagstone Fix, or let our team handle exterior stone with our Facade Cleaning & Sealing service. Share photos on WhatsApp at +91 87792 40420 for advice.