[R] color scale mapped to B/W

[Michael Friendly]

In an R graphic, I'm using

cond.col <- c("green", "yellow", "red")
to represent a quantitative variable, where green means 'OK', yellow 
represents 'warning'
and red represents 'danger'. Using these particular color names, in B/W, 
red is darkest
and yellow is lightest.  I'd like to find color designations to replace 
yellow and green so
that when printed in B/W, the yellowish color appears darker than the 
greenish one.

Is there some tool/code I can use to find these? i.e., something to 
display a grid
of color swatches with color codes/names I can look at in color and B/W 
to decide?

t hanks,


-- 
Michael Friendly     Email: friendly AT yorku DOT ca 
Professor, Psychology Dept.
York University      Voice: 416 736-5115 x66249 Fax: 416 736-5814
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