RRDTool Command:
/usr/local/bin/rrdtool graph - \
--imgformat=PNG \
--start=-86400 \
--end=-300 \
--title="FreeBSD Local Host - httpd open" \
--base=1000 \
--height=120 \
--width=500 \
--alt-autoscale-max \
--lower-limit=0 \
--vertical-label="" \
--slope-mode \
LINE1:#FF0000:"httpd open"  \
GPRINT::LAST:"Current\:%8.2lf %s"  \
GPRINT::AVERAGE:"Average\:%8.2lf %s"  \
GPRINT::MAX:"Maximum\:%8.2lf %s\n" 
RRDTool Says:
ERROR: parameter '#FF0000' does not represent a number in line LINE1:#FF0000:httpd open