While any channel that runs on Roku2 should run fine, if not better, on Roku3, there are a few things you can do to optimize your channels for the new Roku3 experience:
Splash Screen
The Roku3 UI benefits greatly from channels using a full-screen splash screen. If you haven't already, you can include a full-screen splash screen image in your channel package and point to it in the manifest file.
The images should be 1280x720 for HD and 720x480 for SD. In the manifest, you specify them as:
Channel Store Artwork
To make sure that your channel’s icons fit in with the rest of the channel store and look as good as hey can, make sure they follow the following guidelines:
All RGB color values should be between 16 and 235. If you use white as your background, it should have an RGB value of 235,235,235 rather than the 255,255,255 that is the standard for computers. Likewise, black would be 16,16,16 and full green 16,235,26.
Square corners and no transparency
No frames or borders
Include the name of your channel on the artwork with the following guidelines:
No ALL CAPS unless it's a single word (e.g. VEVO)
Channel name should be at least 30px tall (HD) or 20px tall (SD). Any other text (tag lines), should be 23px(hd)/16px(sd) tall.
We recommend all text at least 15px from the top/bottom (HD) or 12px (SD)
Improve Your Web Channel Store Presence
Towards the end of 2012 we introduced a new web-based channel store, available to anyone who visits the Roku website. Searching the channel store on the web will search in channel names, descriptions, and keywords. Updating your descriptions and keywords for the web will help Roku users find your channel and content. Adding or updating your screenshots will help users understand what the your channel is like prior to adding it.
From developer email:
Optimizing Channels for Roku 3
While any channel that runs on Roku2 should run fine, if not better, on Roku3, there are a few things you can do to optimize your channels for the new Roku3 experience:
Splash Screen The Roku3 UI benefits greatly from channels using a full-screen splash screen. If you haven't already, you can include a full-screen splash screen image in your channel package and point to it in the manifest file.
The images should be 1280x720 for HD and 720x480 for SD. In the manifest, you specify them as:
splash_screen_hd=pkg:/images/Splash_HD.jpg splash_screen_sd=pkg:/images/Splash_SD43.jpg
Channel Store Artwork To make sure that your channel’s icons fit in with the rest of the channel store and look as good as hey can, make sure they follow the following guidelines:
All RGB color values should be between 16 and 235. If you use white as your background, it should have an RGB value of 235,235,235 rather than the 255,255,255 that is the standard for computers. Likewise, black would be 16,16,16 and full green 16,235,26. Square corners and no transparency No frames or borders Include the name of your channel on the artwork with the following guidelines: No ALL CAPS unless it's a single word (e.g. VEVO) Channel name should be at least 30px tall (HD) or 20px tall (SD). Any other text (tag lines), should be 23px(hd)/16px(sd) tall. We recommend all text at least 15px from the top/bottom (HD) or 12px (SD)
Improve Your Web Channel Store Presence Towards the end of 2012 we introduced a new web-based channel store, available to anyone who visits the Roku website. Searching the channel store on the web will search in channel names, descriptions, and keywords. Updating your descriptions and keywords for the web will help Roku users find your channel and content. Adding or updating your screenshots will help users understand what the your channel is like prior to adding it.