First of all, I had to spray a layer of primer to get an homogeneous white colour, not only inside each part but also outside so I would be able to add colour on the plastic body. Secondly I had to cover the outside carefully in order to be able to spray the inner face with a dark grey. I had to use a little brush to paint the white holes after spraying.
Once the inside is ready, I had to prepare every detail to spray the outer face. I covered the main holes of each body from the inner face by tape. I had to be very careful once I sticked both parts not to remove the tape, otherwise would be really difficult to get the holes covered again.
I stuck both parts with a hard glue by using the tabs, the problem was that I had already painted the plastic surface so the chloroform didn’t work. To fill the gaps between the parts I used mastic, and once it became dry and hard I sanded the whole container to get a soft surface. Afterwards, I had to spray every body with several layers of primer in order to get the same finishing in the whole body.
Finally, after mixing a lot of colours, I found the chromatic range that I wanted. I applied a base spray layer using each colour for each determined body, and after it dried I changed the pressure of the tool in order to get a plastic texture.