kurushi,
Here's another tip for you...
Have a look in the "Default Art" folder. If you see images there that you'd prefer to use custom icons for, then go back up into the "Data" folder and create a new folder called "Custom Art"
Now create your custom images and save them into your new "Custom Art" folder, using the same file names as used in the default art folder.
MC will now use your custom images instead of the default ones, and you won't need to worry about update installations over writing your custom images, they will always be used as long as they are there.
The "SmallIcons.png" file can be a little more complex. Below, I've replicated instructions I posted elsewhere for customising only the small "Stack" icons that are part of the SmallIcons.png file. They're quite easy to follow, and therefore, easy to apply to any other subset of the SmallIcons file you care to customise.
For the stack icon list column
* Create a folder called "Custom Resources" in the "Data" folder you find in the MC program files directory.
* Create a new text file inside your "Custom Resources" folder and name it "Images.xml"
* Paste the following text into the Images.xml file and save the changes.
<Images>
<SmallThumbStackTopCollapsed>0</SmallThumbStackTopCollapsed>
<SmallThumbStackTopExpanded>1</SmallThumbStackTopExpanded>
<SmallThumbStackMember>2</SmallThumbStackMember>
</Images>
* Create a new image file 48 pixels wide and 16 pixels high.
* In the first 16x16 area of this file, create your "collapsed stack" icon.
* In the second 16x16 area of this file, create your "stack top, expanded" icon.
* In the third and final 16x16 area of this file, create your "stack member, expanded" icon.
* Save this file as "SmallIcons.png" in your "Custom Art" folder.
* Restart MC and it will use your custom icons in the list column.
In your case above, you have applied global edits to the entire SmallIcons file, so for that case, you simply need to create the "Custom Resources" folder and
copy the Images.xml from default to custom,
then save your modified SmallIcons file into the "Custom Art" folder, and you're sorted.
MC will continue to use your "Custom" files across updates, saving you the need to worry about it, and the provision is there for you to make customisations to a few choice icons from the SmallIcons file and have MC use those, along with the rest of the icons from the file in the Default folder.
Clever, huh?
-marko.