how do i get the color gray

how do i get the color gray on my graph

Answer 1

[Hans Scharler]

As others have pointed out, gray is the result of the Red, Green, and Blue values being equal somewhere between 0 and 1 where black is [0 0 0] and white is [1 1 1].

x = rand(200,4);
y = rand(200,4);

grayColor = [.7 .7 .7];

plot(x, y, 'Color', grayColor)

If you are you used to 255 color values from HTML for example, you can divide by 255 to get a value between 0 and 1. Classic HTML gray is [128, 128, 128].

x = rand(200,4);
y = rand(200,4);

htmlGray = [128 128 128]/255;

plot(x, y, 'Color', htmlGray)

[Steven Lord]

And if you want to select a particular color interactively then hard-code that color value into your app, open the uisetcolor dialog box. Select the shade that matches what you want from the dialog then close the dialog. The color value will be displayed in the Command Window, ready for you to copy and paste into the app.

Answer 2

[Walter Roberson]

Gray is any RGB color with Red, Green, and Blue components all equal, excepting black (all 0's) and white (all components the maximum).

For example,

   plot(x, y, 'Color', [17 17 17])

[Khaled Baha]

it doesnt work

[Walter Roberson]

   plot(x, y, 'Color', uint8([17 17 17]))

or

   plot(x, y, 'Color', [17 17 17]/255)

[Zhe Chen]

must be in the range (0 1)

[Walter Roberson]

Which MATLAB release are you using?

plot(rand(1,5), 'Color', uint8([17 17 17]))
hold on
plot(rand(1,5), 'Color', [17 17 17]/255)
hold off

works for me.

Note that there are some plot attributes that only accept floating point, such as most Alpha values. In that case you would need the /255 form.