/usr/share/plplot5.10.0/tcl/cmap1c.pal is in plplot-tcl 5.10.0-0ubuntu5.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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#ff00ff 00
#0080ff 20
#00ffff 44
#00ff90 54
#fffb00 67
#ff0000 100
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