CAHNGES on "top2" BANNER

Hello Guys
Ive got Questions for "top2" modules.
Url: geschenkkorb24.ch

- I changed "collection_3.jpg" with a test-picture on top2 banner module.

Here my questions:

1. How can I change the font color of this module?
2. My changed picture has got a white background. by mouse hover, the background will be again grey. where can I change it to white?
3. When I add the same picture size with white background, on Firefox are grey line visible. I think it can be solved when I can change to white background.

Thank you guys.

Hello again

I could make some changes via override.

Now...I have two issue:

1. How can I disable/change the grey lines?
2. By mousehover: The background changes to grey. How can I change it to WHITE colors?

URL: geschenkkorb24.ch