Change color on an object

[Charles35075046kzx3]

Hi:

We build leather products.  We ofer a lot of different colors of leather and do not always have time to build a demo in each color.  Better leather has more variation within each leather color, so it is not accurate to just repalce the RGB value.  Is there a way to get a mask of another leather color and repalce the source leather color with another leather color?

Thank you 

Chuck

[Trevor.Dennis]

Easiest way would be to use a Hue/Saturation adjustment layer.

I like to add some Color Samplar points, and read the changed value in the Info panel.  If you have a reference for the RGB values for the different colour versions, then you can adjust the sliders to get as close as possible.  My mantra is tha 'the numbers never lie'.

[Bojan Živković]

Could you please upload a screenshot of your exact actions with the Layers panel expanded and visible?

[Charles35075046kzx3]

Sure, the first picture shows a Portfolio in a brown and the second in a red.

[Bojan Živković]

The challenge here is that the colors are not captured under the same lighting conditions. How would the first color look under the second lighting condition? That's the problem, in my opinion, why simply sampling the color numbers and trying to match them on the second photo won't work. If you capture all the bags in the same studio with the same lighting, then you may be able to match the colors closely. Otherwise, different lighting, setup and even device with different output settings will affect the color accuracy.

I'm not very experienced in this matter, so maybe @D Fosse  can offer more help.

[D Fosse]

Yes, Bojan is right. This is all dependent on the lighting. They have to be shot in identical lighting, and they have to be shot in very diffuse light to avoid reflections and deep shadows.

In the studio I'd do this with large soft boxes and possibly a light tent - but outside on an overcast day usually works pretty well. Just be a bit careful and use your eyes, you can still get direct light source reflections. The red bag has a lot of it, and you need to change the angle to get rid of the most of it.

There's no way to do this numerically. The values change with the angle to the light. Any meaningful comparison will have to be made on surfaces with exactly the same angle to the light.

Also be aware that different colors have different inherent brightness. You can't change a bright yellow to a dark purple just by changing the color component - you have to rebuild the whole tonal curve. It's a lot harder than most people think.

Just to get a baseline for neutral light and exposure, you can use a Colorchecker:

Oh, and use a poarizer. They can be surprisingly effective:

[Charles35075046kzx3 · Accepted solution]

Thank you, was afarid of that 🙂  Means we have to build samples in the other colors to make them correct.

Appreciate the feedback.

[davescm]

Another way, if you do a lot of this, is to build 3D models of the products. Apply the materials and render them for each material. Building the models can take a little time, but after that switching out materials and re-rendering is fast. It also takes into account the reflective nature of the surfaces so replacing a matt surface with a glossy surface would still render correctly.

You can also build materials for 3D from real materials e.g. scans of leather which are delit in software and broken down to their components of BaseColour, Metallness, Roughness, Normal (which accounts for any surface variations such as stippling or scratches).

Dave

[Charles35075046kzx3]

Thank you.  As we figured just going to have to make samples in the colors we build, unfortunately.