Code comments are usually put in the code to clarify something or specify something that is not obvious based on the code itself, right?
In that case, you want to be able to read the comments. that means the comments shouldn't be a few shades away from the background color.
I'm using IntelliJ/PyCharm the Solarized color scheme for IntelliJ. With that as a starting point I chose the "Base 03" tone from Solarized as my comment foreground color.
To correct the comment color:
- Go to File -> Settings -> Editor -> Colors & Fonts -> (Python|JavaScript|$LANG)
- (Optionally) Select "Save As..." to save your improved color scheme as something other than Solarized Light.
- For each "Comment"/"Line Comment"/"Docstring" or similar:
- Uncheck "Italic" and "Bold"
- Click the swatch next to "Foreground" and enter "002b36" in the hexadecimal RGB input
Example:

I went as far as changing the color to red (#dc322f), which has the additional benefit of being the same for Solarized dark and light.