[null,null,["最后更新时间 (UTC)：2025-07-27。"],[],[],null,["# Color roles and tokens\n\nThe Wear Material 3 Expressive color system employs three accent layers\n(primary, secondary, tertiary) for key components and two neutral surface\nlayers. Each role offers a range of values with consistent contrast, enabling\nexpressive yet accessible color combinations for a unified experience across any\ntheme.\nAn example of a color theme with roles.\n\nWhat are color roles?\n---------------------\n\nColor roles are like the \"numbers\" in a paint-by-number canvas. They're the\nconnective tissue between elements of the UI and what color goes where.\n\n- **Color roles are mapped to Material components:** You'll use these color roles whether you're using the static baseline scheme or dynamic color. If your product contains custom components, they'll need to be properly mapped to this set of color roles.\n- **Color roles support accessibility:** The color system is built on more accessible color pairings. These color pairs provide a minimum of 3:1 color contrast.\n- **Color roles are tokenized:** Roles are implemented in design and code through tokens. A design token represents a small, reusable design decision that's part of a design system's visual style.\n\nEssential terms\n---------------\n\nHere are key terms you'll see in the names of color roles:\n\n- **Surface:** A role used for backgrounds and large, low-emphasis areas of the screen.\n- **Primary, Secondary, Tertiary:** Accent color roles used to emphasize or de-emphasize foreground elements.\n- **Container:** Roles used as a fill color for foreground elements like buttons. They shouldn't be used for text or icons.\n- **On:** Roles starting with this term indicate a color for text or icons on top of its paired parent color. For example, on primary is used for text and icons against the primary fill color.\n- **Variant:** Roles ending with this term offer a lower-emphasis alternative to its non-variant pair. For example, outline variant is a less emphasized version of the outline color.\n\nPrimary roles\n-------------\n\n\nPrimary roles are used for key components across the UI, such as the Edge\nHugging buttons, prominent buttons, active states, and icons on the tonal button\nstyles. \n\n\u003cbr /\u003e\n\n\n**Primary**\n\n1. Primary\n2. On-Primary\n\nUse the Primary role for the most important actions in the UI, like primary\nbuttons or calls to action. This color should stand out and be instantly\nrecognizable to guide the user toward key interactions. \n\n**Primary-Dim**\n\n1. Primary-Dim\n2. On-Primary\n\nDim roles are typically used for elements that need to be visually distinct from\nthe primary action but don't require immediate user attention or interaction. \n\n**Primary-Container**\n\n1. Primary-Container\n2. On-Primary-Container\n\nApply Primary Container for background elements like cards or modals to\nhighlight sections or selected states. It helps draw attention to important\ncontent or ongoing activities within the UI.\n\n\u003cbr /\u003e\n\nSecondary roles\n---------------\n\n\nSecondary roles are used for key components across the UI, which are not as\nimportant as the primary role, but still need to stand out. Primary and\nsecondary can be used together in layouts to create differentiation and focus. \n\n\u003cbr /\u003e\n\n\n**Secondary**\n\n1. Secondary\n2. On-Secondary\n\nUse the Secondary role for supporting actions in areas with dense UI, such as\nsecondary buttons or complementary actions. It maintains visibility without\novershadowing primary elements in complex layouts. \n\n**Secondary-Dim**\n\n1. Secondary-Dim\n2. Secondary\n\nThe Secondary-Dim role offers a muted contrast for passive elements in dense\nareas. It complements the secondary color while adding subtle depth, keeping the\nUI clean and helping users navigate. \n\n**Secondary-Container**\n\n1. Secondary-Container\n2. On-Secondary-Container\n\nApply Secondary-Container for organizing secondary elements in dense layouts. It\ncreates structure and separation, ensuring secondary content is distinguishable\nbut not dominant.\n\n\u003cbr /\u003e\n\nTertiary roles\n--------------\n\n\nTertiary roles are used for contrasting accents to balance primary and secondary\ncolors or bring heightened attention to an element such as an input field.\nTertiary roles can also help indicate when content changes or should stand out,\nsuch as a goal being reached. \n\n\u003cbr /\u003e\n\n\n**Tertiary**\n\n1. Tertiary\n2. On-Tertiary\n\nThe Tertiary role is used for drawing attention to key elements. Tertiary roles\nare particularly effective for components that need to stand out, such as\nbadges, stickers, or special action elements. \n\n**Tertiary-Dim**\n\n1. Tertiary-Dim\n2. Tertiary\n\nUse the Tertiary Dim role for buttons or actions that are related to tertiary\nactions yet don't require immediate focus. \n\n**Tertiary-Container**\n\n1. Tertiary-Container\n2. On-Tertiary-Container\n\nApply Tertiary-Container for backgrounds that group tertiary-related content,\nlike collections of badges or stickers. It emphasizes tertiary elements while\nmaintaining balance and structure in the UI.\n\n\u003cbr /\u003e\n\nSemantic roles\n--------------\n\n\nError-Red is used to indicate critical issues as error, delete, and anything\nrelated to emergency. It is designed to draw immediate attention to problems or\nwarnings, ensuring users can quickly identify areas that need corrective action.\nThe tone of Error-Red should maintain sufficient contrast against backgrounds to\nmeet accessibility standards, ensuring it is clearly visible and is\ndistinguishable from other status colors like warnings or success messages. \n\n\u003cbr /\u003e\n\n\n**Error**\n\n1. Error\n2. On-Error\n\nA semantic, yet slightly theme-tinted red, which indicates remove, delete, close\nor dismiss actions, such as Swipe to Reveal. Added as a container alternative\nthat is slightly less alarming and urgent than the error-dim color. \n\n**Error-Dim**\n\n1. Error-Dim\n2. On-Error\n\nA semantic, yet slightly theme-tinted red, which indicates high priority errors\nor emergency actions, such as safety alerts, failed dialog overlays or stop\nbuttons. \n\n**Error-Container**\n\n1. Error-Container\n2. On-Error-Container\n\nLess prominent container color, for components using the error state. Can also\nindicate an active error state which feels less interactive than a filled state,\nsuch as an active emergency sharing button or card, or on a failed overlay\ndialog.\n\n\u003cbr /\u003e\n\nSurface containers and elevation\n--------------------------------\n\n\nSurface containers are key in defining depth and elevation within the UI,\nproviding structure and hierarchy through color, helping to differentiate\ncomponents based on their importance and interaction. \n\n\u003cbr /\u003e\n\n\n**Surface-Container-Low**\n\n1. Surface-Container-Low\n2. On-Surface\n3. On-Surface-Variant\n\nGreat for an expanded container that needs to sit below Surface-Container, such\nas an expanded card in the Notification. Can also be used for non-interactive\ncards, where content still benefits from containment. \n\n**Surface-Container**\n\n1. Surface-Container\n2. On-Surface\n3. On-Surface-Variant\n\nThe default container color for most elements. It provides a neutral, moderate\nelevation, making it suitable for general UI components. \n\n**Surface-Container-High**\n\n1. Surface-Container-High\n2. On-Surface\n3. On-Surface-Variant\n\nIdeal for high-emphasis components that need to sit on top of, or in combination\nwith Surface-Container. This color helps bring focus and hierarchy to critical\nareas in the UI.\n\n\u003cbr /\u003e"]]
