i recently upgraded my Libreoffice from 4.1 to 4.2 from Libreoffice repository but the toolbar and it’s icons are too ugly and annoying… why is that??? anyone can help me with That??? 
it’s look like windows 2000… why is that??? i am using LinuxMint 16 Cinnamon…
(Edit: activated screenshots -AK)
You mean the flat icon set? The lovely flat icon set? 
These have now been included with 4.2 which I’m delighted about, as I have been manually installiing the flat icons for quite a while.
[Update: as @oweng points out in the comments, your screenshot seems to be concerned with some of the UI elements, rather than the icon set per se. Could you perhaps clarify in words in your question exactly what the problem is? “Icons” suggested to me the Sifr set, and my answer goes on in that vein. My sense tallies with @oweng’s, that the toolbar bits you might have in mind are OS dependent, rather than a LibO issue. How did you install 4.2, btw? That would help to know.]
I haven’t got 4.2 yet – although I’m looking forward to it – but you can select your icon set from Tools > Options > View then pick your icon set from “Icon size and style” (second item in left-hand column of options):
I thought this was not supposed to be the default setting, though, so I’m puzzled you got this “out of the box”.
@dajare, while the question does indicate the icon set as undesired, in the second attached screenshot the pull-down mark beside the font size is highlighted because it is using an old style. I do not believe this is a factor of the icon set, but rather the windowing system. It may be a LO bug related to Linux Mint installs.
@owemg - ah, ok. If my attempt at an answer is a mis-fit, we can delete. I was a bit puzzled about the “icons”, though. and I’m sure you’re right about those particular bits being OS dependent. I’m on Mint here, but am going to wait to upgrade until I can get 4.2 from a PPA. I’ve checked, but the latest is the 4.1 PPA that I’m currently using.
@dajare, your answer is fine, I just wanted to point out that little extra detail, so that you can update it :-). It is not the default icon set in the website version, although if it is a PPA version, it is possible the Linux Mint team has made this change, in which case this aspect is not an LO issue.
@oweng - I have made an edit/update. Hope that caught the flavour. Btw - please feel free to edit my posts any time. 
I trust your judgment!
I tried this on Mint 17 but there’s no other choices than Automatic/Human, how do I get the colorful 3D icons back?
Never mind. The solution is to install all the libreoffice-style-* packages. Honestly, the obnoxious resentment that users meet when asking for getting color icons back is really over the top. I guess high contrast B&W icons is good for some systems, but I paid extra for a color monitor, and I’d like to use it.