2 issues with mosaic theme – please help!!

Hello, I have two issues with this theme. I am also new to wordpress and do not understand css very much:

1. I am trying to change the color of the tiles in the footer/header (appearance-theme options-styling). It says you can change the color and when i choose a color, nothing happens.

2. I am trying to put in a table but i want to make it “invisible” so that the lines do not show. I have tried everything in the code (in the text tab) and NOTHING is happening. I always see the border. I have tried <table style=”border: none;”><tbody> and setting the color to “o” and it still shows. Where in the editor can i find the solution for this issue? Do i need to edit the style sheet or can you provide me a specific code in the text tab to make the border lines disappear?

If you can provide me specific instructions/code/location to fix these that would be awesome! Great theme none-the-less!