fine tuning for low precip

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@33806 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/gis/colors/precipitation

@@ -1,5 +1,6 @@
 0       white
-300     224:255:255
+125     158:255:222
+250     200:255:255
 500     cyan
 750     0:0:255
 1000    153:51:255