A small bug in Preview enables to underline/highlight with any color

I found a small bug in Mac OS X Mavericks Preview (version 7.0 (826.4)) yesterday, that enables to underline/highlight with any color. It's not so straightforward, but at least if you really really want to use more colors, you can.
http://apple.stackexchange.com/questions/123164/change-highlight-color-in-mavericks-preview
I rewrite it here:

1. Write any text, or draw a line or any other figure with color 1.
2. Change its color to color 2.
3. Select the highlight or underline tool.
4. Do cmd-z. This should change the text/figure color back to color 1. (If it is not the case, make sure the text you have written is not selected.)
5. You now have the underline/highlight tool selected with the color box accessible. Select your color (even if already selected), then highlight/underline.

Another way:

1. Suppose you want to underline in blue. Highlight something in blue.
2. Right-click on what you just highlighted, and make it underlined instead.
3. Select the underline tool.
4. Do cmd-z twice. This will remove the underline you just did.
5. Underline what you want: it will be underlined in blue! :)

Steps 2 and 3 are actually interchangeable.

This was my Preview bug finding day :) Enjoy!