Protecting the product's colour

The look must not move the product's colour. Then it goes into the edit on one switchable layer, over the live shots only.

The product-colour gate. Apply the look to the approved product still and compare it with the original inside the product's area. The measure is ΔE00 (CIEDE2000), the standard figure for how different two colours look.

• Pass: a mean ΔE00 of 2.0 or less, and 3.5 or less on 95% of the product's area.

• How to measure: read several points on the product with the look on and off, and work out ΔE00 for each pair (steps below).

• On a fail, you choose: tone the look down, or keep the product shots out of the graded range. The product is never painted back.

Applying the look in the edit:

• Graded shots: live shots, by default. Graphics, end cards and built packshots stay ungraded, so brand colours stay exact.

• The layer: one adjustment layer above the cut track and below the overlays, laid over the graded ranges, carrying the .cube (steps below). It can be switched off, swapped or eased in seconds. Mark the graded ranges with range markers (GRADE 1, GRADE 2) so the layer can be laid again after any import.

• If another program renders a version, compare one of its frames with Premiere's at the first grade: programs can interpolate the same LUT slightly differently.

A warm look laid over the whole timeline once shifted a logo's red. Grading only the marked ranges prevents it.

Do it yourself

Measure ΔE00 between the still with and without the look (Photoshop)

1. Open the approved still in Photoshop and add a Color Lookup adjustment layer loading the .cube.

2. Place several Color Samplers on the product (Sample Size 5 by 5 Average; Photoshop holds up to ten samplers), with the Info panel set to Lab.

3. Read each sampler with the layer on and off, and work out ΔE00 for each pair with any CIEDE2000 calculator.

4. With a handful of samplers, read the second limit as "no sampler above 3.5".

Put the look on its adjustment layer (Premiere)

1. On the adjustment layer, choose Lumetri Color › Creative › Look › the .cube.

Sources

• This Guide's own checks.

• The CIEDE2000 colour-difference formula is the CIE's standard.