Is that a new shade of gray? How many do we have now? It looks to me like it's starting to get messy, with too many different variations of gray plus the light blues used for the codemirror gutter and alternate rows in the grid.
Yes, it is a darker shade of gray. Are you concerned with the number of variations on gray, or that the grays are not used appropriately?
Both really.
The shade of gray, I think, doesn't really matter that much and remaining consistent within the app is fine as long as there is sufficient contrast.
The use of gray is intentional. The idea being that the eye should be drawn only to the area the user is actively working on. In the picture the area of focus is the query text editor and the blue bar above it actually draws the eye there. After the user decides they need to inspect the results adding blue there makes those results pop.
Let me state what I think your concerns are:
The application is becoming too monochromatic and washed out
the application is becoming too 'flat'
I think we agree that both of these things could be problematic, my guess is where we don't agree is on the line.
Here are the assumptions we are designing to:
users are going to be on the application for multiple hours per day
a softer aesthetic makes it easier on the eyes for long term use.
color is important to make the product appealing
use of color should be intentional and done to change the users focus.
To my knowledge we haven't don't anything to make the application more or less flat.
