この記事では、SwiftUIで使うColor、UIKitで使うUIColorなど、色に関することを色々とまとめていこうと思います。
Contents
SwiftUIでのColorの使い方
基本的な使い方
以下のように、.foregroundColorや、.backgroundColorなどに指定したりします。
struct ContentView: View {
    var body: some View {
        Rectangle()
            .foregroundColor(Color.red)
    }
}
また、Color自身一つのオブジェクトなので、以下のような使い方もできます。
struct ContentView: View {
    var body: some View {
        Color.red
            .frame(width: 300, height: 300)
    }
}
Colorの省略
代入する値が、Colorと確定している箇所では、Colorを省略することができます。
struct ContentView: View {
    var body: some View {
        Rectangle()
            .foregroundColor(.red)
    }
}
ColorでUIColorを使う
SwiftUIでUIColorを使うこともできます。
以下のように、uicolor:という引数に代入してあげれば使えます。
Color(uiColor: UIColor.red)
ちなみに、uicolor:は省略可能です。
Color(UIColor.red)
もっというと、UIColorも省略可能です。
Color(.red)
なので、Color.redとColor(.red)では、同じように記述しているようで、前者はColor、後者はUIColorとなっております。
Assetsを使う

①Assetsを選択
②プラスボタンをクリック
③Color Setを選択
④名前をつける
⑤Any Appearanceをクリック
⑥  (Show the Attributes inspector)をクリック
 (Show the Attributes inspector)をクリック
⑦Colorを設定
上記のように色を設定したら、その名前を""で書こうとその色が使えます。
Color("originalColor")
RGB、HSVで指定
以下のように記述すると、RGB、HSVで指定できたりします。値は0〜1の間で指定します。
RGB
red: 赤、green: 緑、blue: 青、opacity:透明度
Color(red: 1, green: 0.2, blue: 0.2, opacity: 1)
HSV
hue: 色相、saturation: 彩度、brightness: 明度、opacity:透明度
Color(hue: 0.7, saturation: 0.8, brightness: 0.9, opacity: 1)
色一覧
Color
Standard colors
色はライトモードとダークモードで若干違います。
| color | Light | Dark | 
|---|---|---|
| .red | red: 1.0, green: 0.23, blue: 0.19, opacity: 1.0 | red: 1.0, green: 0.27, blue: 0.23, opacity: 1.0 | 
| .orange | red: 1.0, green: 0.58, blue: 0.0, opacity: 1.0 | red: 1.0, green: 0.62, blue: 0.04, opacity: 1.0 | 
| .yellow | red: 1.0, green: 0.8, blue: 0.0, opacity: 1.0 | red: 1.0, green: 0.84, blue: 0.04, opacity: 1.0 | 
| .green | red: 0.2, green: 0.78, blue: 0.35, opacity: 1.0 | red: 0.19, green: 0.82, blue: 0.35, opacity: 1.0 | 
| .mint | red: 0.0, green: 0.78, blue: 0.75, opacity: 1.0 | red: 0.39, green: 0.9, blue: 0.89, opacity: 1.0 | 
| .teal | red: 0.19, green: 0.69, blue: 0.78, opacity: 1.0 | red: 0.25, green: 0.78, blue: 0.88, opacity: 1.0 | 
| .cyan | red: 0.2, green: 0.68, blue: 0.9, opacity: 1.0 | red: 0.39, green: 0.82, blue: 1.0, opacity: 1.0 | 
| .blue | red: 0.0, green: 0.48, blue: 1.0, opacity: 1.0 | red: 0.04, green: 0.52, blue: 1.0, opacity: 1.0 | 
| .indigo | red: 0.35, green: 0.34, blue: 0.84, opacity: 1.0 | red: 0.37, green: 0.36, blue: 0.9, opacity: 1.0 | 
| .purple | red: 0.69, green: 0.32, blue: 0.87, opacity: 1.0 | red: 0.75, green: 0.35, blue: 0.95, opacity: 1.0 | 
| .pink | red: 1.0, green: 0.18, blue: 0.33, opacity: 1.0 | red: 1.0, green: 0.22, blue: 0.37, opacity: 1.0 | 
| .brown | red: 0.64, green: 0.52, blue: 0.37, opacity: 1.0 | red: 0.67, green: 0.56, blue: 0.41, opacity: 1.0 | 
| .white | red: 1.0, green: 1.0, blue: 1.0, opacity: 1.0 | red: 1.0, green: 1.0, blue: 1.0, opacity: 1.0 | 
| .gray | red: 0.56, green: 0.56, blue: 0.58, opacity: 1.0 | red: 0.56, green: 0.56, blue: 0.58, opacity: 1.0 | 
| .black | red: 0.0, green: 0.0, blue: 0.0, opacity: 1.0 | red: 0.0, green: 0.0, blue: 0.0, opacity: 1.0 | 
| .clear | red: 0.0, green: 0.0, blue: 0.0, opacity: 0.0 | red: 0.0, green: 0.0, blue: 0.0, opacity: 0.0 | 
Semantic colors
| color | Light | Dark | 
|---|---|---|
| .accentColor | red: 0.0, green: 0.48, blue: 1.0, opacity: 1.0 | red: 0.04, green: 0.52, blue: 1.0, opacity: 1.0 | 
| .primary | red: 0.0, green: 0.0, blue: 0.0, opacity: 1.0 | red: 1.0, green: 1.0, blue: 1.0, opacity: 1.0 | 
| .secondary | red: 0.24, green: 0.24, blue: 0.26, opacity: 0.6 | red: 0.92, green: 0.92, blue: 0.96, opacity: 0.6 | 
UIColor
Label colors
| color | Light | Dark | 
|---|---|---|
| .label | red: 0.0, green: 0.0, blue: 0.0, opacity: 1.0 | red: 1.0, green: 1.0, blue: 1.0, opacity: 1.0 | 
| .secondaryLabel | red: 0.24, green: 0.24, blue: 0.26, opacity: 0.6 | red: 0.92, green: 0.92, blue: 0.96, opacity: 0.6 | 
| .tertiaryLabel | red: 0.24, green: 0.24, blue: 0.26, opacity: 0.3 | red: 0.92, green: 0.92, blue: 0.96, opacity: 0.3 | 
| .quaternaryLabel | red: 0.24, green: 0.24, blue: 0.26, opacity: 0.18 | red: 0.46, green: 0.46, blue: 0.5, opacity: 0.18 | 
Fill colors
| color | Light | Dark | 
|---|---|---|
| .systemFill | red: 0.47, green: 0.47, blue: 0.5, opacity: 0.2 | red: 0.47, green: 0.47, blue: 0.5, opacity: 0.36 | 
| .secondarySystemFill | red: 0.47, green: 0.47, blue: 0.5, opacity: 0.16 | red: 0.47, green: 0.47, blue: 0.5, opacity: 0.32 | 
| .tertiarySystemFill | red: 0.46, green: 0.46, blue: 0.5, opacity: 0.12 | red: 0.46, green: 0.46, blue: 0.5, opacity: 0.24 | 
| .quaternarySystemFill | red: 0.45, green: 0.45, blue: 0.5, opacity: 0.08 | red: 0.46, green: 0.46, blue: 0.5, opacity: 0.18 | 
Text colors
| color | Light | Dark | 
|---|---|---|
| .placeholderText | red: 0.24, green: 0.24, blue: 0.26, opacity: 0.3 | red: 0.92, green: 0.92, blue: 0.96, opacity: 0.3 | 
Tint color
| color | Light | Dark | 
|---|---|---|
| .tintColor | red: 0.0, green: 0.48, blue: 1.0, opacity: 1.0 | red: 0.04, green: 0.52, blue: 1.0, opacity: 1.0 | 
Standard content background colors
| color | Light | Dark | 
|---|---|---|
| .systemBackground | red: 1.0, green: 1.0, blue: 1.0, opacity: 1.0 | red: 0.0, green: 0.0, blue: 0.0, opacity: 1.0 | 
| .secondarySystemBackground | red: 0.95, green: 0.95, blue: 0.97, opacity: 1.0 | red: 0.11, green: 0.11, blue: 0.12, opacity: 1.0 | 
| .tertiarySystemBackground | red: 1.0, green: 1.0, blue: 1.0, opacity: 1.0 | red: 0.17, green: 0.17, blue: 0.18, opacity: 1.0 | 
Grouped content background colors
| color | Light | Dark | 
|---|---|---|
| .systemGroupedBackground | red: 0.95, green: 0.95, blue: 0.97, opacity: 1.0 | red: 0.0, green: 0.0, blue: 0.0, opacity: 1.0 | 
| .secondarySystemGroupedBackground | red: 1.0, green: 1.0, blue: 1.0, opacity: 1.0 | red: 0.11, green: 0.11, blue: 0.12, opacity: 1.0 | 
| .tertiarySystemGroupedBackground | red: 0.95, green: 0.95, blue: 0.97, opacity: 1.0 | red: 0.17, green: 0.17, blue: 0.18, opacity: 1.0 | 
Separator colors
| color | Light | Dark | 
|---|---|---|
| .separator | red: 0.24, green: 0.24, blue: 0.26, opacity: 0.29 | red: 0.33, green: 0.33, blue: 0.35, opacity: 0.6 | 
| .opaqueSeparator | red: 0.78, green: 0.78, blue: 0.78, opacity: 1.0 | red: 0.22, green: 0.22, blue: 0.23, opacity: 1.0 | 
Link color
| color | Light | Dark | 
|---|---|---|
| .link | red: 0.0, green: 0.48, blue: 1.0, opacity: 1.0 | red: 0.04, green: 0.52, blue: 1.0, opacity: 1.0 | 
Nonadaptable colors
| color | Light | Dark | 
|---|---|---|
| .darkText | white: 0.0, opacity: 1.0 | white: 0.0, opacity: 1.0 | 
| .lightText | white: 1.0, opacity: 0.6 | white: 1.0, opacity: 0.6 | 
Adaptable colors
| color | Light | Dark | 
|---|---|---|
| .systemBlue | red: 0.0, green: 0.48, blue: 1.0, opacity: 1.0 | red: 0.04, green: 0.52, blue: 1.0, opacity: 1.0 | 
| .systemBrown | red: 0.64, green: 0.52, blue: 0.37, opacity: 1.0 | red: 0.67, green: 0.56, blue: 0.41, opacity: 1.0 | 
| .systemCyan | red: 0.2, green: 0.68, blue: 0.9, opacity: 1.0 | red: 0.39, green: 0.82, blue: 1.0, opacity: 1.0 | 
| .systemGreen | red: 0.2, green: 0.78, blue: 0.35, opacity: 1.0 | red: 0.19, green: 0.82, blue: 0.35, opacity: 1.0 | 
| .systemIndigo | red: 0.35, green: 0.34, blue: 0.84, opacity: 1.0 | red: 0.37, green: 0.36, blue: 0.9, opacity: 1.0 | 
| .systemMint | red: 0.0, green: 0.78, blue: 0.75, opacity: 1.0 | red: 0.39, green: 0.9, blue: 0.89, opacity: 1.0 | 
| .systemOrange | red: 1.0, green: 0.58, blue: 0.0, opacity: 1.0 | red: 1.0, green: 0.62, blue: 0.04, opacity: 1.0 | 
| .systemPink | red: 1.0, green: 0.18, blue: 0.33, opacity: 1.0 | red: 1.0, green: 0.22, blue: 0.37, opacity: 1.0 | 
| .systemPurple | red: 0.69, green: 0.32, blue: 0.87, opacity: 1.0 | red: 0.75, green: 0.35, blue: 0.95, opacity: 1.0 | 
| .systemRed | red: 1.0, green: 0.23, blue: 0.19, opacity: 1.0 | red: 1.0, green: 0.27, blue: 0.23, opacity: 1.0 | 
| .systemTeal | red: 0.19, green: 0.69, blue: 0.78, opacity: 1.0 | red: 0.25, green: 0.78, blue: 0.88, opacity: 1.0 | 
| .systemYellow | red: 1.0, green: 0.8, blue: 0.0, opacity: 1.0 | red: 1.0, green: 0.84, blue: 0.04, opacity: 1.0 | 
Adaptable gray colors
| color | Light | Dark | 
|---|---|---|
| .systemGray | red: 0.56, green: 0.56, blue: 0.58, opacity: 1.0 | red: 0.95, green: 0.95, blue: 0.97, opacity: 1.0 | 
| .systemGray2 | red: 0.68, green: 0.68, blue: 0.7, opacity: 1.0 | red: 0.39, green: 0.39, blue: 0.4, opacity: 1.0 | 
| .systemGray3 | red: 0.78, green: 0.78, blue: 0.8, opacity: 1.0 | red: 0.28, green: 0.28, blue: 0.29, opacity: 1.0 | 
| .systemGray4 | red: 0.82, green: 0.82, blue: 0.84, opacity: 1.0 | red: 0.23, green: 0.23, blue: 0.24, opacity: 1.0 | 
| .systemGray5 | red: 0.9, green: 0.9, blue: 0.92, opacity: 1.0 | red: 0.17, green: 0.17, blue: 0.18, opacity: 1.0 | 
| .systemGray6 | red: 0.95, green: 0.95, blue: 0.97, opacity: 1.0 | red: 0.11, green: 0.11, blue: 0.12, opacity: 1.0 | 
Transparent color
| color | Light | Dark | 
|---|---|---|
| .clear | white: 0.0, opacity: 0.0 | white: 0.0, opacity: 0.0 | 
Fixed colors
| color | Light | Dark | 
|---|---|---|
| .black | white: 0.0, opacity: 1.0 | white: 0.0, opacity: 1.0 | 
| .blue | red: 0.0, green: 0.0, blue: 1.0, opacity: 1.0 | red: 0.0, green: 0.0, blue: 1.0, opacity: 1.0 | 
| .brown | red: 0.6, green: 0.4, blue: 0.2, opacity: 1.0 | red: 0.6, green: 0.4, blue: 0.2, opacity: 1.0 | 
| .cyan | red: 0.0, green: 1.0, blue: 1.0, opacity: 1.0 | red: 0.0, green: 1.0, blue: 1.0, opacity: 1.0 | 
| .darkGray | white: 0.33, opacity: 1.0 | white: 0.33, opacity: 1.0 | 
| .gray | white: 0.5, opacity: 1.0 | white: 0.5, opacity: 1.0 | 
| .green | red: 0.0, green: 1.0, blue: 0.0, opacity: 1.0 | red: 0.0, green: 1.0, blue: 0.0, opacity: 1.0 | 
| .lightGray | white: 0.67, opacity: 1.0 | white: 0.67, opacity: 1.0 | 
| .magenta | red: 1.0, green: 0.0, blue: 1.0, opacity: 1.0 | red: 1.0, green: 0.0, blue: 1.0, opacity: 1.0 | 
| .orange | red: 1.0, green: 0.5, blue: 0.0, opacity: 1.0 | red: 1.0, green: 0.5, blue: 0.0, opacity: 1.0 | 
| .purple | red: 0.5, green: 0.0, blue: 0.5, opacity: 1.0 | red: 0.5, green: 0.0, blue: 0.5, opacity: 1.0 | 
| .red | red: 1.0, green: 0.0, blue: 0.0, opacity: 1.0 | red: 1.0, green: 0.0, blue: 0.0, opacity: 1.0 | 
| .white | white: 1.0, opacity: 1.0 | white: 1.0, opacity: 1.0 | 
| .yellow | red: 1.0, green: 1.0, blue: 0.0, opacity: 1.0 | red: 1.0, green: 1.0, blue: 0.0, opacity: 1.0 | 


