Remove red/yellow/green colour from service metrics graph

[rustyjux]

API Services Portal Issue

User Story

As a API Provider,
I want logical colour conventions on a metrics page
so that I can pay attention to what matters.

Colour for the graph in the Stats section uses an interpolated colour (red/yellow/green), which is undesirable because:

• conflicts with colour of the the graph in the services list (always green)
• suggests that a service with a low portion of total requests has issues (red) which require resolution

Suggestion:

• simply use the same, consistent colour as the graph shown in the services list (color="bc-success")
  • the progress bar size already gives a good indicator of high/low values, no need to also show with colour here