These colored fields float loosely in space - you can easily achieve this effect with the right choice of glass. For the 4 color fields empffehleich intense colors or a very unusual glass, such as the self-fused crystal art glass shown here in clear with orange dots.
For the background glass I have deliberately chosen a softly structured clear glass - here Wissmach Hammer 01. A very nice glass, if you are looking for a pure transparency with a high degree of blur -you should definitely try it.