Timber types used for slide rules

Data:

• The first slide rules were made from Boxwood. The boxwood material was chosen for its yellow-brown color, for the contrast with the imprinted numbers.
• Later on Birchwood, Ebony and Mahogany was used, followed by metal slide rules.
• An excerpt from “Rechenschieber - eine Dokumentation” by Dieter von Jezierski is added to help you with the discussions about the different types of timber.

Questions:

1. Which type of wood is used for my 4 sided English slide rule? Is this Boxwood?
2. But why has the inside of my slide rule a very light color, compared with the outside.
3. Or has the outside of the slide rule been coloured?
4. Does somebody know why and what the advantages, disadvantages are of the different types of timber used?