Atlas currently supports three themes out of the box. See atomics/colors for examples.
$white-static: #fff
$black-static: #000
$text: var(--theme-text)
$text-subtle: var(--theme-text-subtle)
$text-invert: var(--theme-text-invert)
$hyperlink: var(--theme-hyperlink)
$text-glow-high-contrast: var(--theme-text-glow-high-contrast)
$box-shadow-color-light: var(--theme-box-shadow-light)
$box-shadow-color-medium: var(--theme-box-shadow-medium)
$box-shadow-color-heavy: var(--theme-box-shadow-heavy)
$box-shadow-color-extra-heavy: var(--theme-box-shadow-extra-heavy)
$body-background: var(--theme-body-background)
$body-background-medium: var(--theme-body-background-medium)
$body-background-accent: var(--theme-body-background-accent)
$alternate-background: var(--theme-alternate-background)
$alternate-background-medium: var(--theme-alternate-background-medium)
$overlay: var(--theme-overlay)
$overlay-invert: var(--theme-overlay-invert)
$overlay-static: hsla(0deg, 0%, 0%, 0.5)
$border: var(--theme-border)
$border-accent: var(--theme-border-accent)
$card-background: var(--theme-card-background)
$code-header: var(--theme-code-header)
$code-block: var(--theme-code-block)
$inline-code: var(--theme-inline-code)
$control-border: var(--theme-control-border)
$control-border-bottom: var(--theme-control-border-bottom)
$table-header: var(--theme-table-header)
$table-row: var(--theme-table-row)
$table-row-header: var(--theme-table-row-header)
$table-border-dark: var(--theme-table-border-dark)
$facepile-red: var(--theme-facepile-red)
$facepile-teal: var(--theme-facepile-teal)
$facepile-blue: var(--theme-facepile-blue)
$gradient-text-purple: var(--theme-gradient-text-purple)
$gradient-text-blue: var(--theme-gradient-text-blue)
$gradient-vivid-start: var(--theme-gradient-vivid-start)
$gradient-vivid-end: var(--theme-gradient-vivid-end)
$default-hover: var(--theme-hover-base)
$default-hover-invert: var(--theme-body-background-medium)
$border-white-high-contrast: var(--theme-border-white-high-contrast)
$border-yellow-high-contrast: var(--theme-border-yellow-high-contrast)
$code-highlight-background: var(--theme-code-highlight-background)
$visited: var(--theme-visited)
$score-low-off: var(--theme-score-low-off)
$score-low: var(--theme-score-low)
$score-medium-off: var(--theme-score-medium-off)
$score-medium: var(--theme-score-medium)
$score-high-off: var(--theme-score-high-off)
$score-high: var(--theme-score-high)
$primary: var(--theme-primary-base)
$primary-background: var(--theme-primary-background)
$primary-background-glow-high-contrast: var(--theme-primary-background-glow-high-contrast)
$primary-dark: var(--theme-primary-dark)
$primary-hover: var(--theme-primary-hover)
$primary-active: var(--theme-primary-active)
$primary-invert: var(--theme-primary-invert)
$primary-box-shadow: var(--theme-primary-box-shadow)
$secondary: var(--theme-secondary-base)
$secondary-background: var(--theme-secondary-background)
$secondary-background-glow-high-contrast: var(--theme-secondary-background-glow-high-contrast)
$secondary-dark: var(--theme-secondary-dark)
$secondary-hover: var(--theme-secondary-hover)
$secondary-active: var(--theme-secondary-active)
$secondary-invert: var(--theme-secondary-invert)
$secondary-box-shadow: var(--theme-secondary-box-shadow)
$tertiary: var(--theme-tertiary-base)
$tertiary-background: var(--theme-tertiary-background)
$tertiary-background-glow-high-contrast: var(--theme-tertiary-background-glow-high-contrast)
$tertiary-dark: var(--theme-tertiary-dark)
$tertiary-hover: var(--theme-tertiary-hover)
$tertiary-active: var(--theme-tertiary-active)
$tertiary-invert: var(--theme-tertiary-invert)
$tertiary-box-shadow: var(--theme-tertiary-box-shadow)
$success: var(--theme-success-base)
$success-background: var(--theme-success-background)
$success-background-glow-high-contrast: var(--theme-success-background-glow-high-contrast)
$success-dark: var(--theme-success-dark)
$success-hover: var(--theme-success-hover)
$success-active: var(--theme-success-active)
$success-invert: var(--theme-success-invert)
$success-box-shadow: var(--theme-success-box-shadow)
$info: var(--theme-info-base)
$info-background: var(--theme-info-background)
$info-background-glow-high-contrast: var(--theme-info-background-glow-high-contrast)
$info-dark: var(--theme-info-dark)
$info-hover: var(--theme-info-hover)
$info-active: var(--theme-info-active)
$info-invert: var(--theme-info-invert)
$info-box-shadow: var(--theme-info-box-shadow)
$warning: var(--theme-warning-base)
$warning-background: var(--theme-warning-background)
$warning-background-glow-high-contrast: var(--theme-warning-background-glow-high-contrast)
$warning-dark: var(--theme-warning-dark)
$warning-hover: var(--theme-warning-hover)
$warning-active: var(--theme-warning-active)
$warning-invert: var(--theme-warning-invert)
$warning-box-shadow: var(--theme-warning-box-shadow)
$danger: var(--theme-danger-base)
$danger-background: var(--theme-danger-background)
$danger-background-glow-high-contrast: var(--theme-danger-background-glow-high-contrast)
$danger-dark: var(--theme-danger-dark)
$danger-hover: var(--theme-danger-hover)
$danger-active: var(--theme-danger-active)
$danger-invert: var(--theme-danger-invert)
$danger-box-shadow: var(--theme-danger-box-shadow)
$colors: [object Object]
$color-index-base: 1
$color-index-background: 2
$color-index-dark: 3
$color-index-hover: 4
$color-index-active: 5
$color-index-invert: 6
$color-index-box-shadow: 7
$color-index-background-glow-high-contrast: 8
$gradients: [object Object]
$gradient-color-start-index: 1
$gradient-color-end-index: 2