Delta Air Lines updates interior design for plane cabins to include new features in lavatories, mood lighting, memory foam cushions and more.

The airline, which next year will celebrate it centennial anniversary, on Tuesday announced it is embarking on a "nose to tail" redesign of its interior cabins. The refresh includes new seat fabrics and materials, mood lighting throughout the plane, and memory-foam cushioning in some cabins.

There are substantive changes that passengers will appreciate at their seats as the new interiors roll out over the coming years.  Delta was clear about the fact that it will take years – as many as seven – for the entire fleet to be updated,