Question on Changing a Color

[Avzlvlzv]

I take pictures of my fountain pens and mechanical pencils using a light box and a digital camera. Naturally, the backround is white. I would like to be able to change this white color to something else on occasion but don't know how to go about it in Photoshop. I am NOT a power user.
I use Photoshop CS5 64 bit.
Keep in mind that sometimes there is also white in the pen in places and I do not want to change anything at all on the color of the pen.
Thank you

 

[SEI7390]

You need to isolate the background from the pen in the image.
The Pen tool is usually the most accurate and most difficult.

Once you have the pen and the background on different layers you can make adjustments to the image background layer.

 

[siodre]

using blend if may or may not work depending on the image and exposure. but if it does work then it's a very quick and dirty way to change the background.

make a new layer, fill it with your background.
duplicate your layer with the fountain pen and move it on top.
right click on that layer, choose blending options.
at the bottom is two gradients changing from black on the left to white on the right.
move the white triangle to the left, press alt and it will split into two and you can move the two halves of the triangle independently to give you more control.

 

[Fairy]

I think you could use the Wand tool to select the background. And after that use the pen or lesso tool to subtract the parts of the pens that was mistakenly selected.

 

[JgraphNet]

Quick Selection tool will do about the same job as the Wand tool but with a better Anti Alias (edge smoothing) ...
To subtract from selection, press-and-hold the Alt/Opt key down when using the Lasso tool or any other suitable selection tool.
To add to selection, press-and-hold the Shift key.