color matching

[Lee]

I have an image of a red chevy truck. The customer wants to see it in chevy blue. I can change the color without any problems but getting it to match the actual manufactures color blue is another story. I DO have a picture of another blue vehicle from Chevrolet that is the same blue that he wants to see on the truck. I used the eye dropper tool and can get that blue in forground box. How do I get it on the truck? Is there any way?

I have been fooling around with the hue/saturation tool and can get it every shade of blue but the one I want.

Thanks, as always.

 

[Erik]

Photoshop divides the color of an object in a basic colour, called "hue", a vibrancy level called saturation and a brightness.
What you want to do is not change the vibrancy or the brightness, but the basic colour. So paint with your chevvy blue on a new layer, set to the "hue" blending mode.

 

[Stroker]

Paint on a new Layer.
Set Blending Mode to Colour.
Prolly the best route.

edit:
If I get the time, I'll show how to do this with HSB.

 

[Lee]

Thank you, gentlemen. Here's the finished image. Suggestions how it could have been done better are always appreciated.

 

[wbiss]

Great job Lee!

 

[Stroker]

Looks fine to me, Lee.

How do it with HSB (no screencaps).

First thing is to get the offsets. Here are some random values (I'm using Lum in place of Brightness).

Source:
Hue: 128
Sat: 65
Lum: 25

Target:
Hue: 25
Sat: 45
Lum: 50

Offset:
Hue: 128 - 25 = 103
Sat: 65 - 45 = 20
Lum: 25 - 50 = -25

No big deal. Even rough approximations are usually good enough.

Start a new Ad-Layer > HSB.
Use the drop down box and pick a colour close to the Source. With the above Target Hue, Green should be good.
On the right of the dialog, there are three eyedropper things. Pick the one on the left and click on the colour you want to change in the Source picture.
Now, for Hue Sat Lum, enter the Offset values using the sliders.

Things should look pretty good. If not totally happy, there are two major tweaks you can do.

Notice at the bottom of the HSB dialog there are two colour strips. One is a spectrum and the other is kind of a solid colour type thing. If you used the drop down box, there should be some new widgets between the two strips. Like two triangles and two vertical lines. You can slide these around to tweak the area of effect for the HSB changes. You can widen, tighten, and affect the fall-off. Spiffy.

The other major tweak is painting on the HSB Ad-Layer mask. If your Ad-Layer is affecting colours that you don't want it to, just paint it out on the mask. Better to have too much and paint it out than to have not enough. Something like that.

 

[sPECtre]

Thanks, Buzz Stroker!

Nicley done, Lee, but have you tried without the shadows under the car?
Something else to try is a gradient mask onthe reflection, to make it fade...

 

[Sanby]

Good job on the truck. It looks like it looks awesome.

Sanby

 

[Lee]

Thanks guys.

 

[sfm]

nice one Lee
thanks for the tips Stroker
sfm