baitbegger44##,
Your point about color and our perception of space is well taken. MsNomer has a good sense of it and when you step in her van it has an openness and a sense of being bigger than a 136 van might be. In ridesteeps and many others’ defense here I understand that material surfaces are ascetic choices particular to the builder and here we generally avoid any comment that might be seen as criticism.
In the 1970’s I built a stone house with a country-cabin interior that had nearly all surfaces of wood. Nice wood by the way, no plywood or fake panels. A friend with interior decorator skills advised me to add several interior walls with nearly white sheetrock to “give ones eyes a surface to relax on”. I resented it, but with my wife’s urging we did it and that house was such an improved space to live in I have since planned such surfaces into the finishes in anything I build
Interesting topic and probably worthy of another thread. When browsing through commercial class B's all around the same size, I was struck by how much larger some models felt than others and this all comes down to interior design. MsNomer's van is a great example of the use of negative space. Large windows and her well-guarded open space create much of that feeling. A similar trick is to use reflecting surfaces like mirrors, metal trim and gloss finishes. The white walls RD's designer friend recommended is a method of creating a focal point. Lighting is important as well as contrasting colors and shapes.
Putting this all together, I'd consider light colored or neutral doors for the cabinets with maybe the rounded edges that you see in some Eurocamper designs. Top it off with shiny hardware like nickel as RD suggests, and things could look brighter without changing too much of the fine work you've done. Since you've made the choice of side opening doors, sliding latches would be another option to the push button latches.
Something like this maybe:
[ame]https://www.amazon.com/St-Simons-11041-015-Professional-Quality/dp/B0193VWYRI/ref=sr_1_3?s=hi&ie=UTF8&qid=1510307528&sr=1-3&keywords=Sliding+bolt+latch+nickel[/ame]
These are my aesthetics, but above all choices made should be personal to make it your own. Tastes may vary, but as I understand it, good design principles do not.