Themes are new in SharePoint 2010 and they are really easy to use, but modifying them in SharePoint is cumbersome. I recommend using PowerPoint 2010. The first step is to open PowerPoint 2010. If your company has a PowerPoint template, you may want to start with this. Usually, someone has already spent considerable time working on the colors of the template and they will hopefully match up with what you are trying to accomplish with the look and feel. Once in PowerPoint navigate to the Design Tab and go over to the colors as shown below.
You need to click Create New Theme Colors if you want to start from scratch or you can pick one of the built in ones to start with. The best thing about working in PowerPoint is that you get a "preview" of the colors and how they look together
Once you are done, give it a name that means something to you.
You can also change the default fonts (one for heading and one for body) by clicking on the fonts item right below the colors. It is fairly limited (2) but can get you started.
Once you have changed the fonts and colors to suit you, go to File and do a Save As. Then choose Office Theme (.thmx). Save this file and then upload it to the SharePoint Themes gallery of the site collection you want to modify.
You will probably still need to do some to break out the CSS but maybe this can get you headed in the right direction.
#sharepoint #Themes #PowerPoint