Question about color

[wallkerrmartin]

I feel embarrassed asking this,
But I was wondering if there is an easy way to take a specific color (say red) and make a lighter or darker version of that exact color?
Is there a "scientific" exact way to do this? So that the color in a piece is all the same red, but just different shades of that exact red?
In the past I've just used the color picker and above or below a particular color but I'm assuming there is a more accurate way.
Hope this makes sense. Thank you

 

[Eggy]

No need to feel embarrassed, we've all been there.

Open the image, in this case a man with a shirt and make a selection of his shirt



Press CTRL+J the place the selected shirt on his own layer



Add an adjustment layer brightness/contrast



Clip that adjustment layer to the shirt layer so the changes will only affect the shirt layer



play with the sliders until you've got the result you want



Note: this is one of the ways to do this as in PS there are many ways to achieve the same result.

 

[hawkeye]

A more exact method for color replacement:

 

[thebestcpu]

Hi Walkerrmartin

Here is a more geeky answer.

In RGB space Photoshop often describes that pixel characteristics by Hue, Saturation, Luminosity (or loosely brightness)

Hue is the determined by the dominant or largest single value in RGB when the other two are equal and determined by the largest two numbers when they are all different (If they all were the same it is a gray tone with no color).

So if you want every single pixel to have the same Hue, place a Layer above your image, fill it with any non gray color that has the desired hue (you can set the hue directly in the color picker) and then set the blend mode to Hue. The Hue of the upper layer takes precedence while taking the Luminosity and Saturation of the lower Layer in that priority respectively.

In the image below, I created a rainbow gradient horzontally multiplied by a white to black gradient vertically to show a bunch of different colors. In the lower half, the image is duplicated only with a Color Hue of 349 degrees using the technique above

Hope this is helpful

John Wheeler