I have this image: http://hdw.eweb4.com/wallpapers/8091/
What I want to do is replace the blue with another color, say red. I've tried the color replacing tool, but it is not really following the gradient correctly. What would be the easiest way to do this?
Since your source image seems to be composed of only two colors, one lighter than the other, you can use a Gradient Map. This will allow you to assign new swatches to the source image. If you want the original color in the middle, add it to the replacement gradient.
Use the Hue/Saturation tool by selecting image>adjustments>Hue/Saturation and in the opened dialogue box move the hue slider in a new position to replace the color.
what hue slider do is to rotate the color all around the color wheel, and you will notice that some color in the gradient background will change accordingly.
you need to make a new layer then fill it with any color of your choice. once you created the fill color, reduce the opacity and fill to make it transparent.
