Website Redesign Question

OK so I created a site just under 3 months ago and I am now reaching the point where I am getting pretty decent rankings and daily visits. I sell services and my bounce rate is 60-70% most days with little sales.

My site looks boring (don't know why I chose this theme buts its grey and dull) and I want to freshen it up with a brand new template that is colourful etc.

My question is, if I use the same content (h1 tags, title, description and all the rest) will it affect my rankings at all? My current template has very limited space to put any decent content on the main page so I wanted to add a little more to try and improve things.

Any advice would be good.

It may have a minimal impact. Themes are part of your On-Page SEO. That is why some static html pages are best used for serious marketers. Their sites might look dull and ugly but hey, they are ranking good.