Theme options

Concord reads theme.toml beside config.toml and keymap.toml. Named UI Highlight Groups control colors and text modifiers, while [ui.border] controls border shapes. Every group and field is optional.

[highlight.Normal]
foreground = "terminal_default"
background = "terminal_default"

[highlight.FocusBorder]
foreground = "light_magenta"

[highlight.ComposerPickerBorder]
link = "FocusBorder"

[highlight.Selection]
background = "none"

[ui.border]
default = "plain"
composer = "rounded"

Group fields

Field	Type	Meaning
link	group name or "none"	Inherit unset fields from another known group, or detach the built-in link.
foreground	color or "none"	Text, marker, or border color; none clears the foreground after inheritance.
background	color or "none"	Cell background color; none clears the background after inheritance.
bold	boolean	Enable or disable bold.
italic	boolean	Enable or disable italic.
dim	boolean	Enable or disable dim.
underline	boolean	Enable or disable underline.
strikethrough	boolean	Enable or disable strikethrough.

A child inherits only fields it does not set. For example, FocusedPaneBorder inherits the foreground from FocusBorder and adds bold. Setting bold = false explicitly removes inherited bold. A direct field on a child wins over the linked group. foreground = "none" and background = "none" clear that channel after inheritance.

Links may point forward or backward. Link cycles warn and ignore cyclic inheritance instead of stopping startup. Group and field names are exact and case-sensitive. Unknown groups, unknown fields, wrong field types, invalid colors, invalid border shapes, and invalid links warn and are ignored one leaf at a time. Valid sibling fields still apply. Run concord --check-config to see warnings.

Colors

Supported values are none, terminal_default, the 16 canonical ANSI names, or a six-digit RGB value with an optional #.

black, red, green, yellow, blue, magenta, cyan, gray, dark_gray, light_red, light_green, light_yellow, light_blue, light_magenta, light_cyan, white

ANSI values use the terminal palette. none removes the color channel so the style does not overwrite the cell underneath. terminal_default explicitly overwrites it with the terminal's default color. Aliases such as reset, darkgray, and bright_red are not accepted.

Border shapes

Border shape is widget geometry, so it is configured separately from Highlight Group colors and modifiers.

[ui.border]
default = "plain"
pane = "double"
composer = "rounded"
modal = "plain"
picker = "plain"
login = "plain"
message = "rounded"
forum = "rounded"

Field	Built-in default	What it controls
default	plain	Fallback for every omitted surface.
pane	default	Main pane frames.
composer	rounded	Composer frame.
modal	default	Modal popup frames.
picker	default	Composer mention, command, and emoji picker frames.
login	default	Login input and QR frames.
message	rounded	Selected message cards.
forum	rounded	Forum post cards.

Supported shapes are plain, rounded, double, thick, light_double_dashed, heavy_double_dashed, light_triple_dashed, heavy_triple_dashed, light_quadruple_dashed, heavy_quadruple_dashed, quadrant_inside, and quadrant_outside. When [ui.border] is absent, Concord preserves its built-in rounded Composer, message cards, and forum cards, with plain remaining surfaces. When default is set, every omitted surface uses that value. A surface field overrides it.

Border sides remain fixed. Allowing a theme to remove a side would change the inner widget area and break layout calculations. Message and forum cards use the same Ratatui glyph sets as block borders, so their configured shape stays consistent with the other surfaces.

Common semantic groups

These groups describe reusable text meaning. Component groups link to them, so one parent override can update related surfaces without coupling render code to a specific color or modifier.

Group	Built-in style	What it controls
Strong	bold	General strong emphasis.
Emphasis	italic	General prose emphasis.
Muted	dim	Low-emphasis content.
Title	Strong	Parent style for titles.
Heading	Strong	Parent style for section headings.
Decoration	Muted	Tree branches, dividers, and separator glyphs.
Hint	Muted	Guidance, status notices, and overflow summaries.
Description	Muted	Secondary descriptions and inactive detail values.
Shortcut	Muted	Keyboard shortcuts shown beside actions.
Activity	Muted	Member and profile activity details.
ChannelTypeMarker	Muted	Channel and thread type markers, including group-DM and populated-voice markers.
FieldLabel	Muted	Labels for detail and filter fields.
SearchContext	Muted	Parent locations and identifiers appended to search results.
Timestamp	Muted	Parent style for timestamps.
Placeholder	Muted	Empty-state and placeholder text.
Disabled	Muted	Disabled controls and values.
Loading	Muted	Loading-state text.
Edited	Muted, italic	Edited markers.
Unavailable	Muted, strikethrough	Unavailable content.

Linked UI groups

These component groups make broad and narrow customization work together. The link shown is the built-in default.

Group	Default link and additions	What it controls
LoginTitle	Title, cyan foreground	Login screen title.
LoginHint	Muted	Login hints and secondary instructions.
PaneTitle	Title	Main pane titles.
ModalTitle	Title	Popup titles.
ComposerTitle	Title	Composer title.
HeaderTitle	Title, cyan foreground	Header title.
HeaderLabel	Muted	Header labels such as Connected as and Voice.
MessageAuthor	Strong	Message author names.
MessageTimestamp	Timestamp	Message timestamps.
CategoryHeading	Heading	Channel category headings.
MemberGroupHeading	Heading	Complete member group headings, including counts.
MessageSecondary	Muted	Typing status, reply previews, and secondary system-message content.
ForumSecondary	Muted	Forum age, archive, lock, and empty-activity details.
MarkdownHeading1	Heading, cyan foreground	Level-one Markdown headings.
MarkdownHeading2	Heading, underline	Level-two Markdown headings.
MarkdownHeading3	Heading	Level-three Markdown headings.
EmbedAuthor	Emphasis	Embed author line.
EmbedTitle	Strong, blue foreground	Embed title.
EmbedFieldName	Strong, underline	Embed field names.
EmbedFooter	Muted, italic	Embed footer.
CodeBlockBorder	Border, dim	Fenced-code block border. Code text remains controlled by Syntect.
ScrollbarTrack	ScrollbarThumb, dim	Scrollbar track.
UnavailableEmoji	Unavailable	Unavailable emoji in Composer pickers.
HeaderError	Error, bold	Header error state.
HeaderWarning	Warning, bold	Header warning state.
PaneBorder	Border	Unfocused main pane borders.
FocusedPaneBorder	FocusBorder, bold	Focused main pane border.
LoginBorder	FocusBorder	Login input and QR frames.
ComposerBorder	Border	Inactive Composer border.
ActiveComposerBorder	FocusBorder, bold	Active Composer border.
ModalBorder	FocusBorder, bold	Modal popup frames.
ComposerPickerBorder	FocusBorder	Mention, command, and emoji picker frames.
SelectedRow	Selection	Selected rows and picker entries. Set a background on this group or Selection for filled selection.
SelectionMarker	Selection	Selection arrows in list panes and pickers, including the member pane.
ActiveField	cyan foreground, bold	Active form fields, filters, and popup commands without a filled background.
ActiveTab	Selection	Active popup tabs.
MessageSelectedBorder	SelectionBorder	Selected message frame.
ForumBorder	FocusBorder	Unselected forum-post frames.
ForumSelectedBorder	SelectionBorder	Selected forum-post frame and marker.
ImageOverflow	MessageAttachment, bold	Additional-image count labels.
BotBadge	Normal, #5865F2 background, bold	Message bot badge.
PresenceOffline	Normal, dim	Offline and unknown presence.

Changing a parent updates every child that remains linked. Override a child to change one component only. Use link = "none" when a child must stop inheriting from its built-in parent.

Base and content groups

Group	Built-in style	What it controls
Normal	terminal foreground and background	Application canvas, normal fills, and default text base.
Border	dark gray foreground	General structural borders.
FocusBorder	cyan foreground	Parent color for focused surfaces.
Selection	cyan foreground, no background, bold, not dim	Parent style for selected content.
SelectionBorder	green foreground, bold	Parent style for framed selection.
ScrollbarThumb	#AAAAAA foreground	Scrollbar thumbs.
UnreadNotice	cyan foreground, bold	New-message notices and forum counts.
Editing	yellow foreground	Fields while editing.
Reaction	cyan foreground	Reactions not made by the current user.
SelfReaction	yellow foreground	Current-user reactions.
PresenceOnline	green foreground	Online presence.
PresenceIdle	#B48C00 foreground	Idle presence.
PresenceDnd	red foreground	Do Not Disturb presence.
VoiceDisabled	yellow foreground	Self-muted and self-deafened header state.
VoiceConnection	yellow foreground, bold	Active voice connection header state.
FolderFallback	cyan foreground	Server folder without a Discord color.
NavigationActive	green foreground, bold	Currently open navigation destination.
NavigationMentioned	#FFA500 foreground	Mentioned navigation destination.
NavigationNotified	terminal foreground	Notified navigation destination.
NavigationUnread	terminal foreground	Unread navigation destination.
MentionBadge	#FFA500 foreground	Navigation mention counts.
NotificationBadge	terminal foreground	Notification and DM unread counts.
JoinedVoiceChannel	yellow foreground, bold	Joined voice channel.
VoiceSpeaking	green foreground, bold	Active voice speaker.
ReplyPingEnabled	cyan foreground	Enabled reply-ping state.
Tag	cyan foreground	Forum and picker tags.
RelationshipFriend	green foreground	Friend state.
RelationshipIncoming	yellow foreground	Incoming friend request.
RelationshipOutgoing	yellow foreground	Outgoing friend request.
RelationshipBlocked	red foreground	Blocked relationship.
RelationshipNone	terminal foreground, dim	No relationship.
GaugeFill	cyan foreground	Filled option gauges.
MessageBody	terminal foreground	Normal message content and emoji fallback.
MarkdownQuote	dark gray foreground	Markdown quote content.
MarkdownMarker	dark gray foreground	Markdown heading, quote, and list markers.
MessageAttachment	cyan foreground	Attachment summaries.
InlineCode	#FFA500 foreground	Inline code.
MessageLink	cyan foreground, underline	Raw URLs and Markdown links.
MentionSelf	yellow on #5C4C23	Mentions that notify the current user. Colored role mentions keep their Discord foreground.
MentionOther	#C1CEF7 on #28325C	Other user, channel, and uncolored role mentions.
MentionRole	Discord role foreground and derived background	Colored role mentions that do not notify the current user. An explicit background overrides the derived background.
MentionPickerRole	magenta foreground	Role and @everyone picker fallback when Discord supplies no role color.
EmbedGutter	red foreground	Embed gutter fallback when Discord supplies no embed color.
EmbedLink	blue foreground, underline	Links in embeds.
CommandName	MessageSecondary, #5865F2 foreground	Slash command names in system messages.
SystemThreadName	cyan foreground, bold	Actionable thread name in system messages.
PollAnswerSelected	terminal foreground, bold	Current user's selected poll answer.
PollWinner	terminal foreground, bold	Winning poll result.
UnreadBanner	terminal foreground on #5865F2	Unread-message banner.
UnreadDivider	#ED4245 foreground	Unread divider line and label.
ForumPinnedBadge	yellow foreground, bold	Pinned forum-post badge.
Error	red foreground	Failures, destructive actions, and required indicators.
Warning	yellow foreground	Warnings and pending or degraded states.
Success	green foreground	Successful operations.
Info	cyan foreground	Informational feedback.

The complete default configuration, including all linked component groups, is in the collapsible Default theme config section of the project README.

External colors

Nonzero Discord role and server-folder colors override related Highlight Group foregrounds. Group modifiers and configured backgrounds still apply. MentionRole.background replaces the background derived from a role color for non-notifying role mentions. Notifying role mentions use MentionSelf with the Discord role foreground.

Discord embed colors, including black, override EmbedGutter.foreground. EmbedGutter is the fallback when an embed has no color. Syntect controls fenced-code syntax colors and Concord selects its light or dark palette from Normal.background. Selected rows keep Discord and presence foregrounds.