You cannot change the color of text in a table individually. The color of text in a table is related with the content text color so the color of text in a table will same as the color that you have set for content text.
Yes if you are familiar with the Color Names or Color Codes then you can add CSS Code to change the text color of table. For that please go to ‘Appearance > Customize > Additional CSS’ and paste the below code.
.entry-content table {
color: red;
}
please replace the above ‘red’ color with your desired Color Name or Color Code (RGB or Hex).
To change the title background color login to your dashboard and go to Appearance > Customize > Colors > Elements Color there you can see Site Title Area option to change the site title background color.