You need to find where roAppManager is used to set the application theme.
In my videoplayer example, it's all pretty obvious where it is and what to change, in the file:
https://github.com/belltown/Roku-NewVideoPlayer/blob/master/source/UITheme.brs'********************************************************************
'
' NewVideoPlayer -- Example Multi-Level Roku Channel
'
' Copyright (c) 2015, belltown. All rights reserved. See LICENSE.txt
'
'********************************************************************
'
' Initialize the application-wide theme
'
Function uiThemeInit () As Void
darkGrey = "#333333"
white = "#b0b0b0"
offWhite = "#8a8a8a"
lightGrey = "#aaaaaa"
mediumGrey = "#666666"
darkWhite = "#525252"
'
' Dark theme customizations for roPosterScreen and roSpringboardScreen
'
darkTheme = {
' No logos in this implementation ...
REM OverhangPrimaryLogoSD: "pkg:/images/OverhangPrimaryLogoSD.png"
REM OverhangPrimaryLogoOffsetSD_X: "55"
REM OverhangPrimaryLogoOffsetSD_Y: "34"
REM OverhangPrimaryLogoHD: "pkg:/images/OverhangPrimaryLogoHD.png"
REM OverhangPrimaryLogoOffsetHD_X: "123"
REM OverhangPrimaryLogoOffsetHD_Y: "0"
FilterBannerSliceSD: "pkg:/images/FilterSliceSD-1x38-1f1f1f.png" ' solid, single color value of #1f1f1f
FilterBannerSliceHD: "pkg:/images/FilterSliceHD-1x60-1f1f1f.png" ' solid, single color value of #1f1f1f
OverhangSliceSD: "pkg:/images/OverhangSliceSD-1x83.png" ' solid, single color value of #414a4c
OverhangSliceHD: "pkg:/images/OverhangSliceHD-1x124.png" ' solid, single color value of #414a4c
GridScreenOverhangSliceSD: "pkg:/images/OverhangSliceSD-1x83.png" ' solid, single color value of #414a4c
GridScreenOverhangSliceHD: "pkg:/images/OverhangSliceHD-1x124.png" ' solid, single color value of #414a4c
GridScreenOverhangHeightSD: "83" ' Grid Screen overhang height (breadcrumb area)
GridScreenOverhangHeightHD: "124" ' Grid Screen overhang height (breadcrumb area)
BackgroundColor: darkGrey ' Background color
BreadcrumbTextLeft: "#777777" ' Text color for leftmost breadcrumb (will vary with overhang slice color)
BreadcrumbTextRight: "#BBBBBB" ' Text color for rightmost breadcrumb (will vary with overhang slice color)
ButtonMenuHighlightText: white ' Text color for selected button on roSpringboardScreen
ButtonMenuNormalText: offWhite ' Text color for non-selected button on roSpringboardScreen
ButtonHighlightColor: white ' Text color for selected button on roParagraphScreen
ButtonNormalColor: offWhite ' Text color for non-selected button on roParagraphScreen
PosterScreenLine1Text: white ' Text color for ShortDescriptionLine1 on roPosterScreen
PosterScreenLine2Text: offWhite ' Text color for ShortDescriptionLine2 on roPosterScreen
SpringboardTitleText: lightGrey ' Text color for Title on roSpringboardScreen
SpringboardRuntimeColor: mediumGrey ' Text color for Length, ReleaseDate, and Rating on roSpringboardScreen
SpringboardActorColor: white ' Text color for Actors on roSpringboardScreen
SpringboardDirectorColor: lightGrey ' Text color for Director on roSpringboardScreen
SpringboardDirectorLabelColor: mediumGrey ' Text color for Director label on roSpringboardScreen
SpringboardDirectorText: "director" ' Text used as the Director label on roSpringboardScreen
SpringboardGenreColor: mediumGrey ' Text color for Genres on roSpringboardScreen
SpringboardSynopsisColor: lightGrey ' Text color for Description on roSpringboardScreen
FilterBannerActiveColor: white ' Text color for the selected filter banner item when active
FilterBannerInactiveColor: white ' Text color for the selected filter banner item when inactive
FilterBannerSideColor: darkWhite ' Text color for the non-selected filter banner item
}
CreateObject ("roAppManager").SetTheme (darkTheme)
End Function
The roAppManager theme attributes are documented in:
http://sdkdocs.roku.com/display/sdkdoc/roAppManager It's not immediately obvious what some of them do, so you may need to do some experimenting. Look at the comments in my code above for additional clues.