[TimoJ]

That makes sense, depending on your original input: I hope you tested with a picture. With kodi set to Full - the original value should come out - means if you have a full range RGB grey ramp: Black is 0. If your Black is already 16 - then it's clear that it gets 20 when you additionally enable Use Limited. Cause the 16 in full range is a dark grey, so in Limited it needs to be 20, cause if it was 16 there as well the original dark grey would now be black -> not what we want.

^^ This is true for pictures in full range. For Video (especially hw decoded ones) it's different.

 It was a full range picture, you can get it from here: https://www.cs.cmu.edu/afs/cs/project/se...mg1024.gif
I still think it's not shown correctly. Kodi GUI in limited mode is not mapping full range 16 to 20, it's mapping it to a lower than 16 value and makes it invisible.   

 We found the issue. Expect a PR today - something like that:

Code:

 diff --git a/xbmc/guilib/GUITextureGL.cpp b/xbmc/guilib/GUITextureGL.cpp
index e8eb0ec998..139c530331 100644
--- a/xbmc/guilib/GUITextureGL.cpp
+++ b/xbmc/guilib/GUITextureGL.cpp
@@ -53,9 +53,9 @@ void CGUITextureGL::Begin(UTILS::Color color)

if (m_renderSystem->UseLimitedColorRange())
{
- m_col[0] = (235 - 16) * m_col[0] / 255 + 16.0f / 255.0f;
- m_col[1] = (235 - 16) * m_col[1] / 255 + 16.0f / 255.0f;
- m_col[2] = (235 - 16) * m_col[2] / 255 + 16.0f / 255.0f;
+ m_col[0] = (235 - 16) * m_col[0] / 255 + 16.0;
+ m_col[1] = (235 - 16) * m_col[1] / 255 + 16.0;
+ m_col[2] = (235 - 16) * m_col[2] / 255 + 16.0;
}

bool hasAlpha = m_texture.m_textures[m_currentFrame]->HasAlpha() || m_col[3] < 255;

And btw. you were right with the brighter vs. darker, stay tuned - and thx for your help. Highly appreciated.  

OK, and thank you!