When I clikd the time to see the date it's always in what looks like grey scale and is always hard to read comparte to the time. I can't find any thing in prefs to make the date more legible.
That's the Apple default colour code. Grey means something you can't choose / click on it. If you can't read it.
System preferences -> accessibility -> display -> increase contrast may help.
If you still can't read it, adjust the "display contrast" may help.
OR
You can simply tick the "show date" option inside the Date and Time preferences. So that the date display constantly on the menu bar with "easier to read" colour.