Start by downloading the Legacy theme, and applying it.
It will add files to the Hub’s HD, in this path:
/.wd_tv/theme/Legacy
Edit the file called rv_gallery_browse_page.xml
Comment out the following line, as illustrated:
<?xml version=“1.0”?>
<page background=“./image/RV-BG.jpg”>
<image image=“image/keyboard_mask_bg.png” x=“0” y=“0” w=“1280” h=“720” bg=“1” disable=“@@disable-thumbnail-bg”/>
<!-- disable background>
<image image=“@@preview_rect_image” default_image=“@@default_preview_rect_image” x=“0” y=“0” w=“1280” h=“720” textcolor=“@@preview_rect_color” keycolor=“1” ignore_keycolor=“1” bg=“1”/>
<disable background–>
<image image=“image/Gallery/video_browse_gallery_overlay.png” x=“0” y=“0” w=“1280” h=“720” bg=“1”/>
…
…
That will then just show the default background image, which is fairly dark and shouldn’t interfere with reading the text.
Let me know how this works for you.