[theme] Improve default theme dark colors #18776
Description
- The issue is present in the latest release.
- I have searched the issues of this repository and believe that this is not a duplicate.
Current Behavior 😯
The primary and secondary colors are identical between the light and dark theme.
Expected Behavior 🤔
The color should becomes less saturated as in the demos of the documentation and as specified by the Material Design specification.
Steps to Reproduce 🕹
https://codesandbox.io/s/material-ui-dark-theme-41nm4
Your Environment 🌎
| Tech | Version |
|---|---|
| Material-UI | v4.7.2 |
| React | 16.12.0 |
| Browser | Chrome Version 78.0.3904.108 (Official Build) (64-bit) |