Changeable color on portable apps skin?

When you said "icon" you got me a bit confused for a second, but I see you obviously mean how the menu pops up from the icon. So here's what you do

At this link, you'll find an original post by John Haller.

https://portableapps.com/node/4571

Near the bottom of the bost, there are two highlighted downloads calledDownload Portable Apps Menu 1.0.2 Beta 3 (Pre-Release 2) and Download Portable Apps Menu 1.0.2 Beta 3 (Pre-Release 2) Source. Extract both of these files to your X:PortableApps/PortableApps/PortableApps Menu (Directory).

Next, go to this Forum topic, where'll you find MULTIPLE links for theme downloads, as well, there's a vista theme, if you search vista theme in the search box of the top right corner of this site, ad in John Haller's post, there's also a black theme I believe. The link for the main theme topic is:

https://portableapps.com/node/4605

From here, you extract the theme you've downloaded, and copt the files, most themes will only have files like background, background top, and drive space slider, as well as a read me, copy THESE files to: X:PortableApps/PortableApps/PortableApps Menu/App/DefaultData/Theme. (Directory) Paste the files in there, and click yes to overwrite the old ones. BUT, yuo first may want to back up the original theme. For icons included in some packages, copy the PAM icons to ..........App/DefaultData/Icon Theme, for icons for the actual documents area of your USB, I believe you copy them to .......App/DefaultData/Folder icons, and PortableAppsMenu/Icons.

I hoped this helped.
Next time, just search in the search box (Top right corner of this site)