To begin, you need Numenor's CEP if you want to recolor items that only come in one color in the game. You can get it off modthesims2.com
Secondly, you need SimPE. Google "SimPE" and it should be the first thing to come up.
And last, you need a decent photo editting program. I'm going to use photoshop. MS PAINT WILL NOT WORK!
Once you have all that, you're ready to begin!
Go into your SimPE file and open "Wizards of SimPE"
Click 'Recolors'. [This is the only option I have, so I assume it would be the same for you]
Decide what you'd like to recolor. I think I'll make a couch. Search through the items until you find what you want. **The three circles, usually misc., has a lot of stuff that really can't be recolored. I'd stay out, unless you're looking to recolor a door or window]
I'll be using the Club Distress Sofa, so the pattern will work on the chair and loveseat.
Click the item you want, then hit the red next at the bottom.
You'll get a page like this:
Click on the one that's most like your desired pattern. I'm working on a haunted house, so I'll be making a gray one. I'll pick the 'ivory' color.
Click next and you'll get this:
Click on your texture and click export. A window will open up, giving you an option of where to save it to. Save it to somewhere you can find it easily and give it a good name. I have an items folder specifically for this, so I'll save there.
Go to that folder and your texture should be there.
Open it with your editting program. Make any adjustments you'd like. I'll be fixing it's saturation and burning it a little. [If you aren't good with the program, you may might to google some tutorials. If you have photoshop or Microsoft Digital Imaging Suite 9, feel free to PM me and I'll be glad to help!]
When you've completed your changes, save it and go back to Wizards of simPE. Click import, and the file you saved to will open. Import the texture and it should appear where the old image once was.
Click next again. Type in a name for your creation [just so you know what it will appear as] and click save. Congratulations, you now have your very own recolor! If you ever want to remove it, go into your downloads folder and simply delete it [it will be whatever you saved it as on the last step.]
Using these very simple method, you can create all sorts of recolors!
For additional help, reply to this thread or PM me.
