Working With Colors

You will occasionally want to validate the colour of something as part of your tests; the problem is that colour definitions on the web are not constant. Would it not be nice if there was an easy way to compare a HEX representation of a colour with a RGB representation of a colour, or a RGBA representation of a colour with a HSLA representation of a colour?

Worry not. There is a solution: the Color class!

First of all, you will need to import the class:

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import org.openqa.selenium.support.Color;
  
from selenium.webdriver.support.color import Color

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include Selenium::WebDriver::Support

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import org.openqa.selenium.support.Color

You can now start creating colour objects. Every colour object will need to be created from a string representation of your colour. Supported colour representations are:

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private final Color HEX_COLOUR = Color.fromString("#2F7ED8");
private final Color RGB_COLOUR = Color.fromString("rgb(255, 255, 255)");
private final Color RGB_COLOUR = Color.fromString("rgb(40%, 20%, 40%)");
private final Color RGBA_COLOUR = Color.fromString("rgba(255, 255, 255, 0.5)");
private final Color RGBA_COLOUR = Color.fromString("rgba(40%, 20%, 40%, 0.5)");
private final Color HSL_COLOUR = Color.fromString("hsl(100, 0%, 50%)");
private final Color HSLA_COLOUR = Color.fromString("hsla(100, 0%, 50%, 0.5)");
  
HEX_COLOUR = Color.from_string('#2F7ED8')
RGB_COLOUR = Color.from_string('rgb(255, 255, 255)')
RGB_COLOUR = Color.from_string('rgb(40%, 20%, 40%)')
RGBA_COLOUR = Color.from_string('rgba(255, 255, 255, 0.5)')
RGBA_COLOUR = Color.from_string('rgba(40%, 20%, 40%, 0.5)')
HSL_COLOUR = Color.from_string('hsl(100, 0%, 50%)')
HSLA_COLOUR = Color.from_string('hsla(100, 0%, 50%, 0.5)')

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HEX_COLOUR = Color.from_string('#2F7ED8')
RGB_COLOUR = Color.from_string('rgb(255, 255, 255)')
RGB_COLOUR = Color.from_string('rgb(40%, 20%, 40%)')
RGBA_COLOUR = Color.from_string('rgba(255, 255, 255, 0.5)')
RGBA_COLOUR = Color.from_string('rgba(40%, 20%, 40%, 0.5)')
HSL_COLOUR = Color.from_string('hsl(100, 0%, 50%)')
HSLA_COLOUR = Color.from_string('hsla(100, 0%, 50%, 0.5)')

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private val HEX_COLOUR = Color.fromString("#2F7ED8")
private val RGB_COLOUR = Color.fromString("rgb(255, 255, 255)")
private val RGB_COLOUR_PERCENT = Color.fromString("rgb(40%, 20%, 40%)")
private val RGBA_COLOUR = Color.fromString("rgba(255, 255, 255, 0.5)")
private val RGBA_COLOUR_PERCENT = Color.fromString("rgba(40%, 20%, 40%, 0.5)")
private val HSL_COLOUR = Color.fromString("hsl(100, 0%, 50%)")
private val HSLA_COLOUR = Color.fromString("hsla(100, 0%, 50%, 0.5)")

The Color class also supports all of the base colour definitions specified in http://www.w3.org/TR/css3-color/#html4.

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private final Color BLACK = Color.fromString("black");
private final Color CHOCOLATE = Color.fromString("chocolate");
private final Color HOTPINK = Color.fromString("hotpink");
  
BLACK = Color.from_string('black')
CHOCOLATE = Color.from_string('chocolate')
HOTPINK = Color.from_string('hotpink')

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BLACK = Color.from_string('black')
CHOCOLATE = Color.from_string('chocolate')
HOTPINK = Color.from_string('hotpink')

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private val BLACK = Color.fromString("black")
private val CHOCOLATE = Color.fromString("chocolate")
private val HOTPINK = Color.fromString("hotpink")

Sometimes browsers will return a colour value of “transparent” if no colour has been set on an element. The Color class also supports this:

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private final Color TRANSPARENT = Color.fromString("transparent");
  
TRANSPARENT = Color.from_string('transparent')

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TRANSPARENT = Color.from_string('transparent')

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private val TRANSPARENT = Color.fromString("transparent")

You can now safely query an element to get its colour/background colour knowing that any response will be correctly parsed and converted into a valid Color object:

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Color loginButtonColour = Color.fromString(driver.findElement(By.id("login")).getCssValue("color"));

Color loginButtonBackgroundColour = Color.fromString(driver.findElement(By.id("login")).getCssValue("background-color"));
  
login_button_colour = Color.from_string(driver.find_element(By.ID,'login').value_of_css_property('color'))

login_button_background_colour = Color.from_string(driver.find_element(By.ID,'login').value_of_css_property('background-color'))

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login_button_colour = Color.from_string(driver.find_element(id: 'login').css_value('color'))

login_button_background_colour = Color.from_string(driver.find_element(id: 'login').css_value('background-color'))

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val loginButtonColour = Color.fromString(driver.findElement(By.id("login")).getCssValue("color"))

val loginButtonBackgroundColour = Color.fromString(driver.findElement(By.id("login")).getCssValue("background-color"))

You can then directly compare colour objects:

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assert loginButtonBackgroundColour.equals(HOTPINK);
  
assert login_button_background_colour == HOTPINK

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assert(login_button_background_colour == HOTPINK)

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assert(loginButtonBackgroundColour.equals(HOTPINK))

Or you can convert the colour into one of the following formats and perform a static validation:

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assert loginButtonBackgroundColour.asHex().equals("#ff69b4");
assert loginButtonBackgroundColour.asRgba().equals("rgba(255, 105, 180, 1)");
assert loginButtonBackgroundColour.asRgb().equals("rgb(255, 105, 180)");
  
assert login_button_background_colour.hex == '#ff69b4'
assert login_button_background_colour.rgba == 'rgba(255, 105, 180, 1)'
assert login_button_background_colour.rgb == 'rgb(255, 105, 180)'

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assert(login_button_background_colour.hex == '#ff69b4')
assert(login_button_background_colour.rgba == 'rgba(255, 105, 180, 1)')
assert(login_button_background_colour.rgb == 'rgb(255, 105, 180)')

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assert(loginButtonBackgroundColour.asHex().equals("#ff69b4"))
assert(loginButtonBackgroundColour.asRgba().equals("rgba(255, 105, 180, 1)"))
assert(loginButtonBackgroundColour.asRgb().equals("rgb(255, 105, 180)"))

Colours are no longer a problem.

Last modified September 12, 2023: replace code alerts with tabpanes that have code badges in each tab (59dc7de8fa6)