Colors for probability and impact are not consistent

[eric-intuitem]

Describe the bug
There is no specification for colors of probability and impact in the specification and in imported matrices, only of the colour of the risk. However, the current implementation uses colours for probability and impact based on id number. This leads to inconsistent behaviour, e.g. for the 5x5 sensitive matrix when putting almost certain x severe (grey colour for both).

Expected behavior
A consistent specification and implementaition.
Solution 1: add colour definition in the json definition for probability and impact.
Solution 2: do not use colours for probability and impact.

As solution 2 can be a special case of solution 1 (no colour given in the definition), solution 1 is preferred.

Additional context
Add any other context about the problem here.