Created attachment 81067 [details]
Kick Off Launcher Plasma Widget showing poorly rendered fonts alongside same text typed and copied from Kate, with nicer font rendering.

Kick Off uses grayscale sub-pxel font rendering, even though Use Sub-pixel rendering | RGB is selected in System Settings.

Please see the attached image, which shoes actual fonts rendered in in Kick Off.  The image also shows the same text typed and copied from Kate.

Subjectively, on my LCD (and to my eyes) the Kick Off fonts look fuzzy, while the Kate fonts look sharp.

Objectively, zoom into the image, and notice that the Kick Off fonts have gray fringes, indicating that Grayscale Sub-Pixel rendering has been applied.  Scroll to the right, while zoomed in, and notice that the Kate fonts have colored fringes, indicating that RGB Sub-Pixel rendering has been applied.

To Reproduce...

    Make sure ~/.fonts.conf does not exist.
    Launch System Settings
    Select Application Appearance
    Select Fonts
    Select Use anti-aliasing
    Select Enabled
    Click Configure
    Uncheck Exclude range
    Check Use sub-pixel rendering
    Select RGB from dropdown
    Select Hint style Full from dropdown
    Click OK
    Click Apply
    Restart machine (just to make sure settings are applied)

Verify...
    Take a screen shot of Kick Off.
    Zoom into the image, and verify that the Kick Off fonts have gray fringes, indicating that Grayscale Sub-Pixel rendering has been applied, even though you selected Use sub-pixel rendering | RGB in System Settings.