Use the text.col argument as below
?legend
x=y=1:100
z=seq(0.5,50,by=0.5)
plot(x,y,type='l',col='black')
lines(x,z,col='red')
legend('topleft',c(expression(paste(alpha," = ", 1)),
expression(paste(alpha," = ",
2))),text.col=c("black","red"))
> Date: Thu, 28 Jul 2011 02:32:04 -0500
> From: zhongyi-yuan@uiowa.edu
> To: r-help@r-project.org
> Subject: [R] color of math annotation in legend
>
> Dear useRs,
>
> Can someone help me to adjust the color of math annotation in a legend? The
> following code gives me a black "alpha = 2".
>
> x=y=1:100
> z=seq(0.5,50,by=0.5)
> plot(x,y,type='l',col='black')
> lines(x,z,col='red')
> legend('topleft',c(expression(paste(alpha," = ", 1)),
> expression(paste(alpha," = ",
2))),col=c('black','red'))
>
> Is it possible to make it red? Thanks in advance for your help.
>
> Best,
> Zhongyi Yuan
>
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>
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