diff --git a/runtime/doc/api.txt b/runtime/doc/api.txt
index ced0b2d181..5e7c467c43 100644
--- a/runtime/doc/api.txt
+++ b/runtime/doc/api.txt
@@ -1555,8 +1555,9 @@ nvim_set_hl({ns_id}, {name}, {val})                            *nvim_set_hl()*
                  accepts the following keys:
                  • altfont: boolean
                  • bg: color name or "#RRGGBB", see note.
-                 • bg_indexed: boolean (default false) If true, bg is a
-                   terminal palette index (0-255).
+                 • bg_indexed: boolean. If true, `bg` is an RGB approximation
+                   of `ctermbg` (a palette index). UIs rendering cterm
+                   natively may prefer `ctermbg`.
                  • blend: integer between 0 and 100
                  • blink: boolean
                  • bold: boolean
@@ -1571,8 +1572,8 @@ nvim_set_hl({ns_id}, {name}, {val})                            *nvim_set_hl()*
                    |:hi-default|
                  • dim: boolean
                  • fg: Color name or "#RRGGBB", see note.
-                 • fg_indexed: boolean (default false) If true, fg is a
-                   terminal palette index (0-255).
+                 • fg_indexed: boolean. Same as `bg_indexed`, for `fg` and
+                   `ctermfg`.
                  • force: boolean (default false) Update the highlight group
                    even if it already exists.
                  • italic: boolean
diff --git a/runtime/lua/vim/_meta/api.gen.lua b/runtime/lua/vim/_meta/api.gen.lua
index c32a554e2b..47a7d5b86a 100644
--- a/runtime/lua/vim/_meta/api.gen.lua
+++ b/runtime/lua/vim/_meta/api.gen.lua
@@ -2225,7 +2225,8 @@ function vim.api.nvim_set_decoration_provider(ns_id, opts) end
 --- @param val vim.api.keyset.highlight Highlight definition map, accepts the following keys:
 --- - altfont: boolean
 --- - bg: color name or "#RRGGBB", see note.
---- - bg_indexed: boolean (default false) If true, bg is a terminal palette index (0-255).
+--- - bg_indexed: boolean. If true, `bg` is an RGB approximation of `ctermbg`
+---   (a palette index). UIs rendering cterm natively may prefer `ctermbg`.
 --- - blend: integer between 0 and 100
 --- - blink: boolean
 --- - bold: boolean
@@ -2237,7 +2238,7 @@ function vim.api.nvim_set_decoration_provider(ns_id, opts) end
 --- - default: boolean Don't override existing definition `:hi-default`
 --- - dim: boolean
 --- - fg: Color name or "#RRGGBB", see note.
---- - fg_indexed: boolean (default false) If true, fg is a terminal palette index (0-255).
+--- - fg_indexed: boolean. Same as `bg_indexed`, for `fg` and `ctermfg`.
 --- - force: boolean (default false) Update the highlight group even if it already exists.
 --- - italic: boolean
 --- - link: Name of highlight group to link to. `:hi-link`
diff --git a/runtime/lua/vim/_meta/api_keysets_extra.lua b/runtime/lua/vim/_meta/api_keysets_extra.lua
index 0ac48e80da..5eecd7bc39 100644
--- a/runtime/lua/vim/_meta/api_keysets_extra.lua
+++ b/runtime/lua/vim/_meta/api_keysets_extra.lua
@@ -152,13 +152,15 @@ error('Cannot require a meta file')
 --- @field background? integer
 
 --- @class vim.api.keyset.get_hl_info : vim.api.keyset.hl_info.base
---- @field fg? integer
---- @field bg? integer
---- @field sp? integer
---- @field default? true
---- @field link? string
 --- @field blend? integer
+--- @field bg? integer
+--- @field bg_indexed? boolean
 --- @field cterm? vim.api.keyset.hl_info.cterm
+--- @field default? true
+--- @field fg? integer
+--- @field fg_indexed? boolean
+--- @field link? string
+--- @field sp? integer
 
 --- @class vim.api.keyset.set_hl_info : vim.api.keyset.hl_info.base
 --- @field fg? integer|string
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index c39f177bd9..467b382d8f 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -139,7 +139,8 @@ DictAs(get_hl_info) nvim_get_hl(Integer ns_id, Dict(get_highlight) *opts, Arena
 /// @param val   Highlight definition map, accepts the following keys:
 ///                - altfont: boolean
 ///                - bg: color name or "#RRGGBB", see note.
-///                - bg_indexed: boolean (default false) If true, bg is a terminal palette index (0-255).
+///                - bg_indexed: boolean. If true, `bg` is an RGB approximation of `ctermbg`
+///                  (a palette index). UIs rendering cterm natively may prefer `ctermbg`.
 ///                - blend: integer between 0 and 100
 ///                - blink: boolean
 ///                - bold: boolean
@@ -151,7 +152,7 @@ DictAs(get_hl_info) nvim_get_hl(Integer ns_id, Dict(get_highlight) *opts, Arena
 ///                - default: boolean Don't override existing definition |:hi-default|
 ///                - dim: boolean
 ///                - fg: Color name or "#RRGGBB", see note.
-///                - fg_indexed: boolean (default false) If true, fg is a terminal palette index (0-255).
+///                - fg_indexed: boolean. Same as `bg_indexed`, for `fg` and `ctermfg`.
 ///                - force: boolean (default false) Update the highlight group even if it already exists.
 ///                - italic: boolean
 ///                - link: Name of highlight group to link to. |:hi-link|
diff --git a/src/nvim/highlight.c b/src/nvim/highlight.c
index 0f5bbb91cc..99f0d8d56c 100644
--- a/src/nvim/highlight.c
+++ b/src/nvim/highlight.c
@@ -757,7 +757,7 @@ int hl_blend_attrs(int back_attr, int front_attr, bool *through)
       cattrs.rgb_sp_color = -1;
     }
 
-    cattrs.rgb_ae_attr &= ~HL_BG_INDEXED;
+    cattrs.rgb_ae_attr &= ~(HL_FG_INDEXED | HL_BG_INDEXED);
   }
 
   // Check if we should preserve background transparency
@@ -916,8 +916,8 @@ Dict hl_get_attr_by_id(Integer attr_id, Boolean rgb, Arena *arena, Error *err)
 void hlattrs2dict(Dict *hl, Dict *hl_attrs, HlAttrs ae, bool use_rgb, bool short_keys)
 {
   hl_attrs = hl_attrs ? hl_attrs : hl;
-  assert(hl->capacity >= HLATTRS_DICT_SIZE);  // at most 16 items
-  assert(hl_attrs->capacity >= HLATTRS_DICT_SIZE);  // at most 16 items
+  assert(hl->capacity >= HLATTRS_DICT_SIZE);  // at most 24 items
+  assert(hl_attrs->capacity >= HLATTRS_DICT_SIZE);  // at most 24 items
   int mask = use_rgb ? ae.rgb_ae_attr : ae.cterm_ae_attr;
 
   if (mask & HL_INVERSE) {
@@ -999,14 +999,12 @@ void hlattrs2dict(Dict *hl, Dict *hl_attrs, HlAttrs ae, bool use_rgb, bool short
       PUT_C(*hl, short_keys ? "sp" : "special", INTEGER_OBJ(ae.rgb_sp_color));
     }
 
-    if (!short_keys) {
-      if (mask & HL_FG_INDEXED) {
-        PUT_C(*hl, "fg_indexed", BOOLEAN_OBJ(true));
-      }
+    if (mask & HL_FG_INDEXED) {
+      PUT_C(*hl, "fg_indexed", BOOLEAN_OBJ(true));
+    }
 
-      if (mask & HL_BG_INDEXED) {
-        PUT_C(*hl, "bg_indexed", BOOLEAN_OBJ(true));
-      }
+    if (mask & HL_BG_INDEXED) {
+      PUT_C(*hl, "bg_indexed", BOOLEAN_OBJ(true));
     }
   } else {
     if (ae.cterm_fg_color != 0) {
diff --git a/src/nvim/highlight_defs.h b/src/nvim/highlight_defs.h
index 2cb1dc603b..d777e8ff80 100644
--- a/src/nvim/highlight_defs.h
+++ b/src/nvim/highlight_defs.h
@@ -179,4 +179,4 @@ typedef struct {
 #define COLOR_ITEM_INITIALIZER { .attr_id = -1, .link_id = -1, .version = -1, \
                                  .is_default = false, .link_global = false }
 
-enum { HLATTRS_DICT_SIZE = 20, };
+enum { HLATTRS_DICT_SIZE = 24, };
diff --git a/test/functional/api/highlight_spec.lua b/test/functional/api/highlight_spec.lua
index 0c4b911167..d02e198d1a 100644
--- a/test/functional/api/highlight_spec.lua
+++ b/test/functional/api/highlight_spec.lua
@@ -679,6 +679,29 @@ describe('API: get highlight', function()
     api.nvim_set_hl(0, 'Bar', { link = 'Foo', default = true, force = true })
     eq({ link = 'Foo', default = true }, api.nvim_get_hl(0, { name = 'Bar' }))
   end)
+
+  it('round-trips fg_indexed/bg_indexed through nvim_get_hl', function()
+    api.nvim_set_hl(0, 'Test_idx', {
+      fg = '#cc0000',
+      bg = '#0000cc',
+      ctermfg = 1,
+      ctermbg = 4,
+      fg_indexed = true,
+      bg_indexed = true,
+    })
+    local hl = api.nvim_get_hl(0, { name = 'Test_idx' })
+    eq(true, hl.fg_indexed)
+    eq(true, hl.bg_indexed)
+    eq(tonumber('0xcc0000'), hl.fg)
+    eq(tonumber('0x0000cc'), hl.bg)
+    eq(1, hl.ctermfg)
+    eq(4, hl.ctermbg)
+
+    api.nvim_set_hl(0, 'Test_idx', { fg_indexed = false, update = true })
+    eq(nil, api.nvim_get_hl(0, { name = 'Test_idx' }).fg_indexed)
+    eq(true, api.nvim_get_hl(0, { name = 'Test_idx' }).bg_indexed)
+    eq(tonumber('0xcc0000'), api.nvim_get_hl(0, { name = 'Test_idx' }).fg)
+  end)
 end)
 
 describe('API: set/get highlight namespace', function()