The "QUERY VARIABLES" string is hard to spot in the API console in dark theme

Created by: indradhanush

• Sourcegraph version: 90376_2021-03-17_2aad55a
• Platform information: Chromium 89.0.4389.90 Arch Linux) and Firefox (Mozilla Firefox 86.0.1)

Steps to reproduce:

1. Visit https://sourcegraph.com/api/console
2. Switch to dark theme

Expected behavior:

The text color for QUERY VARIABLES should be similar to one of the following in this screenshot:

Actual behavior: