The roof looked one colour on the sample board. Across the house, a dark rectangle has developed a personality of its own. You can see it every time you reverse out of the driveway.

Distinguish the blend from a mismatch

IKO's colour-variation bulletin explains the importance of blend codes and checking bundles before installation. Follow the current instructions for the exact product. Different manufacturers and product lines do not necessarily use the same packaging conventions.

  • Photograph the complete product name, colour name and blend code on any retained wrappers. IKO says different blend codes should not be mixed on the same roof, even when the colour name matches.
  • Keep the full production code visible in the photograph. Ask the supplier to identify the production dates rather than guessing from an unfamiliar code.
  • Keep the delivery record and wrapper installation instructions with those photos. Ask the roofer which deliveries went onto each slope, if that information is available.

The same IKO bulletin says manufacturing oils and powders can cause temporary colour variation that weathers away. Ask the manufacturer whether the observed pattern fits that explanation and when it should be reviewed again.

Keep a useful record before debating the remedy

Take ground-level photographs under comparable dry lighting and retain wrappers or label photos if available. Ask the contractor to identify the installed product and obtain manufacturer guidance. Do not pressure-wash, coat, or otherwise alter the shingles to disguise a difference. Appearance and weather resistance are separate questions to assess.

Before the next step

  • Record the pattern safely from the ground.
  • Retain product, colour, blend, and delivery information.
  • Request a written assessment before accepting a proposed remedy.

A new roof is a large surface to shrug at. Good records make a colour concern easier to investigate without assuming either a defect or a harmless variation.

For choosing the original blend, compare roof material and colour choices; a small sample and an installed colour patch are different questions.