Removing text and image white outline

[Ori]

Hi everyone,

I'm trying to use an object container as a bulletin board,

it displays several text and image objects, each with an insight.

I've encountered an annoying issue with the outline of each text box.

No matter what I try I cant seem to remove each box's white outline.

example :

Does anyone have an idea on how to remove it and use the same background color as the container?

Thanks.