This is a relatively simple method of dulling down colors and really can give a photo an interesting effect. I’ve seen it performed on photos of people with great sucess. I’ll be using a boring snapshot of a goose, Canadian type I believe, trying to get some bread.
Remember, don’t use your original file, it is always best to make a copy of a photo you want to edit on so you dont destroy your original!
We will be using the channel mixer for this. I tend to use adjustment layers instead of duplicating a layer and applying the channel mixer to it. The adjustment layers can be found in your layer toolbox and the button you need to look for is a circle, half black, half white. Choose the channel mixer option shown below.
What you want to do now is to make sure the “monochrome” option is checked. This will turn your color photo into a black and white photo. From here on this will require alot of experimentation. First thing you want to do is lower the slider bar for the “constant” value. Then you can increase the other color values until you arrive at a rather contrasty type black and white photo. Contrasty is what we’re looking for. Press Ok when you are done.
The final step in muting the colors is to make sure the adjustment layer is selected in your layers toolbox, and then mess around with your opacity settings and your fill settings until you get the effect you like the most.
Hope you enjoyed this little tutorial. Remember, experimentation never hurts as long as you dont save over your original file. 
Got comments? Leave a comment below. Tell me if you enjoyed this tutorial or if it was helpful. Comments keep me writing. Thanks.
Well, as you know, I don’t pp, but I wanted to let you know that I’m stopping by every day to see what’s new here! Looks like you’re doing great and you’ve got a good thing going.