respect plasma theme color palette always

--identify better what is the plasma theme color
palette the creator has chosen and use ALWAYS
the same color palette that Plasma is also using.
In the past, Latte was trying to protect the
color palette because Latte REVERSED colors mode
did not work fine for all plasma themes. That
approach is abandoned, Latte will use the same
colors group with plasma themes and it is on
the creators responsibility to provide enough
contrast