Diffuse and Ambient colour, texture, or procedurals must be in sync.  Diffusion and Ambience values must also be in sync and are regarded as just 'one' value called the DA value.

The DA value should always be 100 unless you introduce Reflection or Transparency.  DA and Reflection or DA and Transparency need to be balanced so that their total does not exceed or fall below 100.

Note how Reflection is in balance with the DA value in both screenshots (their total is 100).  If you had not used Reflection at all, the DA value would need to be 100 to keep the balance correct.