The image should represent the different parts of a lymph node in an aesthetic way.
Cells should also be depicted in each part of the lymph node where they are usually present in significant quantity.
The lymph node is composed of areas where specific events occur to initiate an adaptative immune response. Each part will be identified with a specific color and should be visible even if cells are placed above it.
The style should present a sense of simplicity even if there will be a lot of elements on it.
To translate the idea that the lymph node is a 3D object full of cells, it would be great to present several layers on top of each other.
To add clarity while also allowing to depict a lot of elements, the lymph node can have a glass material. It would also add a certain originality and transmit the idea that we are looking through a 3D object (alike looking through a lens for instance).
The rest of the composition should be simple to avoid distraction from the main subject which is the centerpiece.
Colors chosen to have contrast between cell types and the different structures of the lymph node. These colors also add a modern touch because they differ from the common colors used to depict organs.