Disable color shading in Task Page Perf Table

When viewing perf tables in an Evergreen task page with a comparison, the rows are colored based on the assumption that higher is better. Numbers greater than 100 are green, and those below are red. For the latency values reported by expanded metrics, this is not correct. This ticket is to disable the coloring entirely in the table.

Task Link
Acceptance Criteria:

• No more red/green colors in task page perf table charts.
• Previously red/green columns should be colored with alternating grey/white the same way the other columns are.