[R] colors, lines, characters .... documentation

[Monica Palaseanu-Lovejoy]

Hi,

Very so often when i am plotting something, doing a histogram, or 
whatever i am struggling to find out which are the numbers for 
different colors, palette names, types of lines, symbols, etc. Is 
there any documentation on line with all these numbers / names 
and the associated symbol / color???

For example if i am using the command image it uses a palette 
from red to yellow, with red the lowest value, and yellow the highest 
value. What if i want a reverse palette, with green the lowest value 
and yellow middle values and red highest value??? Or much more 
simple, just yellow lowest value and red highest value???

Thank you for assistance,

Monica