Overhaul the look and feel of an Excel Spreadsheet

We recently introduced a new Project quality gate system (MS Excel based) for our Software delivery process. Despite the scoring mechanism working very well for me and my team, I feel the overall look and feel still needs a far more professional look that will also encourage usage. The general layout and positioning of the various elements are OK, it's mainly the colours, font usage, overall consistency and readability between the tabs I need overhauled. The final product should have corporate look without being over the top! This is no a large design project, but I just do not have the time to do it and therefore your professional design expertise are required. See the excel attached and send me your bids within the budget range specified! Any spreadsheets/projects you have revamped will be considered before I choose a freelancer.