setColor

(Not recommended) Set color used to draw ROI object

setColor is not recommended. With the new ROIs, set the value of the Color property instead. For more information, see Version History.

Syntax

setColor(h,color)

Description

setColor(h,color) sets the color used to draw the ROI object h.

Examples

Set Color of Polygon ROI

Display an image. Draw a polygon on the image, specifying the location of five vertices.

imshow("gantrycrane.png")
h = impoly(gca,[188,30; 189,142; 93,141; 13,41; 14,29]);

Set the color of the polygon to yellow.

setColor(h,"yellow");

Input Arguments

h — ROI object

imellipse | imfreehand | imline | impoint | impoly | imrect

ROI object, specified as an imellipse, imfreehand, imline, impoint, impoly, or imrect object.

color — ROI color

RGB triplet | color name | short color name

ROI color, specified as an RGB triplet, a color name, or a short color name.

You can specify any color using an RGB triplet. An RGB triplet is a 3-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0, 1].

You can specify some common colors by name as a string scalar or character vector. This table lists the named color options and the equivalent RGB triplets.

Color Name	Short Name	RGB Triplet	Appearance
"red"	"r"	[1 0 0]
"green"	"g"	[0 1 0]
"blue"	"b"	[0 0 1]
"cyan"	"c"	[0 1 1]
"magenta"	"m"	[1 0 1]
"yellow"	"y"	[1 1 0]
"black"	"k"	[0 0 0]
"white"	"w"	[1 1 1]

This table lists the default color palettes for plots in the light and dark themes.

Palette	Palette Colors
"gem" — Light theme default Before R2025a: Most plots use these colors by default.
"glow" — Dark theme default

You can get the RGB triplets for these palettes using the orderedcolors function (since R2023b). For example, get the RGB triplets for the "gem" palette.

RGB = orderedcolors("gem");

Example: "r"

Example: "green"

Example: [0 0.4470 0.7410]

Version History

Introduced in R2008a

R2018b: setColor is not recommended

Starting in R2018b, a new set of ROI objects replaces the existing set of ROI objects. The new objects provide more functional capabilities, such as face color transparency. The new classes also support events that you can use to respond to changes in your ROI such as moving or being clicked. Although there are no plans to remove the old ROI objects at this time, switch to the new ROIs to take advantage of the additional capabilities and flexibility. For more information on creating ROIs using the new ROI functions, see Create ROI Shapes.

To set the color of the new ROIs, set the value of the Color property.

Update Code

Update all instances of setColor.

Discouraged Usage	Recommended Replacement
This example creates an ROI and uses setColor to specify the color of the ROI. imshow("cameraman.tif"); h = imrect(gca,[10 10 100 100]); setColor(h,"yellow");	Replace the ROI with the equivalent new ROI object. Then, delete the call to setColor and set the value of the Color property of the ROI. imshow("cameraman.tif"); h = drawrectangle(gca,"Position",[10 10 100 100]); h.Color = "yellow"