Homekit Panel Card (HACS) Configuration problem

Hi Guys,

i downloaded the Homekit Panel Card from HACS and it is looking very nice.
At the configuration i got a little problem:

i want to change the title color and the configuration tutorial says it should be possible with “titleColor”
But if i change that to a dark grey (#1c1c1c) the text is not changing the color.

What i am doing wrong?

Thanks for your help.