How can I use ONLY the central 90% of the spectrum, not the whole range? For example, I do not like to see the lowest values in purple, but in deep blue color.
tzvw={{394.5, 0.58, -0.56391}, {394.5, 0.56, -0.580086}, {394.5,
0.54, -0.56415}, {394.5, 0.52, -0.561491}, {394.5,
0.5, -0.572876}, <<3267>>, {90557.4, 0.1, -0.358004}, {90557.4,
0.08, -0.2929}, {90557.4, 0.06, -0.240185}, {90557.4,
0.04, -0.211586}, {90557.4, 0.02, -0.156428}}
ShowLegend[
ListContourPlot[tzvw,
ColorFunction -> ColorData["Rainbow"],
Contours -> Range[-2.25, 2.75, 0.25], ContourLines -> False,
FrameTicks -> {ticklst, Automatic, None, None},
PlotRange -> {Automatic, {0, 0.52}, {-2.25, 2.75}}, FrameStyle -> 20,
AspectRatio -> 0.3, ImageSize -> 700,
"DelaunayDomainScaling" -> True,
RegionFunction -> Function[{x, y, z}, y <= 0.5]]
tzvw
). $\endgroup$