Added documentation and whatsnew

Author: tehunter

doc/source/user_guide/style.ipynb

@@ -1594,8 +1594,9 @@
     "\n",
     "\n",
     "- Only CSS2 named colors and hex colors of the form `#rgb` or `#rrggbb` are currently supported.\n",
-    "- The following pseudo CSS properties are also available to set excel specific style properties:\n",
+    "- The following pseudo CSS properties are also available to set Excel specific style properties:\n",
     "    - `number-format`\n",
+    "    - `border-style` (for Excel-specific styles: \"hair\", \"mediumDashDot\", \"dashDotDot\", \"mediumDashDotDot\", \"dashDot\", \"slandDashDot\", or \"mediumDashed\")\n",
     "\n",
     "Table level styles, and data cell CSS-classes are not included in the export to Excel: individual cells must have their properties mapped by the `Styler.apply` and/or `Styler.applymap` methods."
    ]
@@ -2026,7 +2027,7 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3 (ipykernel)",
+   "display_name": "Python 3.10.4 ('pandas-testing')",
    "language": "python",
    "name": "python3"
   },
@@ -2040,7 +2041,12 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.5"
+   "version": "3.10.4"
+  },
+  "vscode": {
+   "interpreter": {
+    "hash": "99ba7404bdbf380b6668594445346cc49dc5e126b0bc53947f71689e253b4235"
+   }
   }
  },
  "nbformat": 4,

doc/source/whatsnew/v1.5.1.rst

@@ -23,7 +23,8 @@ Fixed regressions
 
 Bug fixes
 ~~~~~~~~~
--
+- Bug in :class:`CSSToExcelConverter` leading to error when unrecognized ``border-style`` (including ``"hair"``) provided to Excel writers (:issue:`48649`)
+- Bug in :class:`CSSToExcelConverter` where border would not fall back on black when border style or width provided without a color (:issue:`48649`)
 -
 
 .. ---------------------------------------------------------------------------