UIColor Extension Reference


                    
                    
                    contrastRatio(to:)

Contrast ratio between two colors according to W3’s WCAG 2.0: https://www.w3.org/TR/WCAG20/#contrast-ratiodef

Declaration

Swift

public func contrastRatio(to otherColor: UIColor) -> CGFloat

Parameters


                                otherColor

the color to calculate contrast ratio with

Return Value

the contrast ratio between the two colors ranging from 1.0 (identical) to 21.0 (the contrast between pure white and pure black)


                    
                    
                    isSufficientContrast(to:context:level:)

Determines whether the contrast between this UIColor and the provided UIColor is sufficient to meet the recommendations of W3’s WCAG 2.0.

The recommendation is that the contrast ratio between text and its background should be at least 4.5 : 1 for small text and at least 3.0 : 1 for larger text.

Warning

Combining context == .uiComponent and level == .AAA will return false for all color pairings because there is no AAA contrast threshold level defined for UI Components.

Declaration

Swift

public func isSufficientContrast(
    to otherColor: UIColor,
    context: WCAGContext = .normalText,
    level: WCAGLevel = .AA
) -> Bool

Parameters

`otherColor`	the other color to compute contrast with
`context`	the context of the color comparison (default = `.normalText`)
`level`	the WCAG standard to test against (default = `.AA`)

Return Value

true if the two colors meet the specified WCAG minimum contrast ratio, otherwise false


                    
                    
                    lightened(by:)

Lightens the receiving color by blending it with white.

Warning

The receiving color must be addressible in the rgba color space.

Declaration

Swift

func lightened(by amount: CGFloat = 0.5) -> UIColor

Parameters


                                amount

the amount of white to blend in, ranging from 0 (0% white) to 1 (100% white). The value is constrained to a minimum of 0 and a maximum of 1. Default = 0.5 (50% white).

Return Value

The lightened color


                    
                    
                    darkened(by:)

Darkens the receiving color by blending it with black.

Warning

The receiving color must be addressible in the rgba color space.

Declaration

Swift

func darkened(by amount: CGFloat = 0.5) -> UIColor

Parameters


                                amount

the amount of black to blend in, ranging from 0 (0% black) to 1 (100% black). The value is constrained to a minimum of 0 and a maximum of 1. Default = 0.5 (50% black).

Return Value

The darkened color


                    
                    
                    blended(by:with:)

Blends the receiving color with another color.

Warning

Both colors must be addressible in the rgba color space.

Declaration

Swift

func blended(by amount: CGFloat = 0.5, with otherColor: UIColor) -> UIColor

Parameters

`amount`	the amount of the other color to blend in, ranging from 0 (0% other color) to 1 (100% other color). The value is constrained to a minimum of 0 and a maximum of 1. Default = 0.5 (50/50 blend of each color).
`otherColor`	the other color to blend with the receiving color

Return Value

The blended color


                    
                    
                    init(rgb:alpha:)

Create a color from a RGB hex value

Declaration

Swift

public convenience init(rgb: UInt, alpha: CGFloat = 1.0)

Parameters

`rgb`	RGB hex value (anything about 0xFFFFFF will be masked out and ignored)
`alpha`	alpha value


                    
                    
                    rgbaComponents

Returns the RGBA color channel components for this color. Values range from 0.0 to 1.0 in the sRGB color space.

Declaration

Swift

var rgbaComponents: RGBAComponents { get }


                    
                    
                    rgbDisplayString(prefix:isUppercase:)

Formats a color as an RGB hexadecimal string

Declaration

Swift

func rgbDisplayString(prefix: String? = nil, isUppercase: Bool = true) -> String

Parameters

`prefix`	optional prefix to precede the hexadecimal value such as `0x` or `#` (default = nil)
`isUppercase`	whether the hex values should be upper or lower case

Return Value

the formatted hexadecimal string


                    
                    
                    rgbDebugDisplayString(prefix:isUppercase:)

Formats a color as an RGB hexadecimal string. Appropriate for debug printing.

Declaration

Swift

func rgbDebugDisplayString(prefix: String? = nil, isUppercase: Bool = true) -> String

Parameters

`prefix`	optional prefix to precede the hexadecimal value such as `0x` or `#` (default = nil)
`isUppercase`	whether the hex values should be upper or lower case

Return Value

the formatted hexadecimal string (with an ⚠️ for colors that fall outside of the sRGB color space)