It is kind of default vbulletin skin. Either you buy vbulletin or go for free mybb which has some vbulletin skins...
i have bought vbulletin. look please, this is my forum türkçe sohbet türkçe forum but i wanna use this skin.
you mean green one ? ... get the graphics sdk from vbulletin.com and change the colors to green like DP
It`s easy to make style like this. Make screen shot to any page and get the colours codes from any design program and create new style using this codes.
login to vbulletin.org there you will find one similar green skin. I'll try n find a link for you and post it here.
If you want to learn how to make one ... install vb on your computer. from control panel Styles & Templates>>Style Manager Press Go side Default Style Don`t care about first two tables now(Common Templates,Sizes and Dimensions) Start with Body. Change Background color code to this one #21DE26(it`s very green one ), save CSS. Go to your forum home and see the difference,you are knowing now what exactly this change done. Just play with the other tables trying to change the colors.It will take two hours max. to have good idea about every table and what it do. After that make screen shot to DP forums and get the colors codes via photoshop, put it in the right places and you will get DP style. Just two images you have to modify, the gradiant images. It`s really easy, just give it a try!