It is an old post.
Still might be of use to someone.
Ensure the monitor brightness controls are set correctly.
Windows 10 settings.
As stated by others, try picking a bright color box in the Windows color swatches.
Next, ensure transparency effects is turned off. That will brighten taskbar a little.
Ensure "Show accent color" is turned on for start, taskbar, action center.
IT at work is usually behind in Windows 10 updates for compatibility/security reasons.
If by some chance your company has upgraded to latest Creators Update,
you can try the extra feature called "Custom color".
Adjust the slider to the right anywhere as long as the text "This color is not supported"
does not show. Click on "Done" to save the setting.
It will affect the color on the start menu though.
Too bad Microsoft does not have any idea that some people like the taskbar to be a brighter value.
If nothing above has helped, try this:
If your IT department lets you install a start menu program,
use Classic Shell, or one of the new names for it Open-Shell. One can set options to have the regular Windows 10 menu show,
and be able to change the color/brightness of just the taskbar to anything you want.
taskbar text.