/usr/share/plplot5.10.0/cmap1_default.pal is in libplplot12 5.10.0+dfsg-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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#5500ff 0 0
#110033 44 0
#010005 50 0
#050000 50 0
#330000 56 0
#ff0000 100 0
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