Okay So Let me just tell you each step I've done so you can point out if I've missed or done something wrong.
I want to recolor a custom painting not a game based painting.

I open SimPE. I open .package file of painting.
I go to plugin view of texture (there is only 1 texture).
I import new texture.
Update all sizes. > commit.
Go to file > save as and name new .package file.

*Repeat process for different recolors. Always opening first original package.

Recolors are not showing up in game.
Using object workshop doesn't work either for some reason.
The paintings show up with numbers that look like binary code and a big red x on it.

Did I do something wrong?

Oh and yes, they are in the downloads folder.

You can't just change the texture and save as a new name. Each recolor package must have a unique internal file name. You must use object workshop to recolor EAxis and custom files, this will give your recolor it's unique internal name. Start OW, then select open, and browse to your custom painting, then start.

I did that before, I went to object workshop, hit start once opening package.
Saved new name of package.
Imported new texture in plugin view.
Updated all sizes.
Commit changes.
File>save.

In game the recolors would show up with binary code and red x on it.


**edit:**

to show you what I mean here is a picture:



This is what happens when I do the steps above using object workshop.

That means the links to the texture in the package are not correct. You are choosing recolor, then opening the custom painting in OW right? And does the original painting work correctly in your game? And is recolorable? And you must open the package via OW not the File/Open menu in SimPE, this is how you opened it right? Have you read through this tutorial? http://www.modthesims.info/showthread.php?t=102356

Yes I am trying to recolor these posters:

http://www.modthesims.info/download.php?t=45647

I start object workshop, open custom .package file.
Make sure recolor is selected. Create CEP is checked as well, I have the correct CEP files installed.
Name new package when saving window comes up.
Select texture image, which is only 1 image.
Go to plugin view > select import.
Import new texture > Update all sizes.
Commit changes > Save



and on numenor's tutorial, It says to import using build dxt but the option is faded in the menu when I right click the image, so I can't use it.

*****EDIT****

I used photostudio and that seemed to work. Don't know what the difference is between using photostudio and object workshop other than photostudio is specifically for paintings.

Thanks for your help!

If I may hijack this thread, this is my first time trying to recolor a custom painting and I had the same results as above. How do I import the custom painting into Photo Studio in order to recolor it? Do I have to clone it first?