Index: src/wp-content/themes/twentytwenty/style-rtl.css
===================================================================
--- src/wp-content/themes/twentytwenty/style-rtl.css	(revision 56020)
+++ src/wp-content/themes/twentytwenty/style-rtl.css	(working copy)
@@ -3351,6 +3351,10 @@
 
 /* Block: Table ------------------------------ */
 
+.wp-block-table table:where(:not(.has-text-color)) * {
+	border-color: inherit;
+}
+
 .wp-block-table.is-style-stripes tbody tr:nth-child(odd) {
 	background: #dcd7ca;
 }
Index: src/wp-content/themes/twentytwenty/style.css
===================================================================
--- src/wp-content/themes/twentytwenty/style.css	(revision 56020)
+++ src/wp-content/themes/twentytwenty/style.css	(working copy)
@@ -3371,6 +3371,10 @@
 
 /* Block: Table ------------------------------ */
 
+.wp-block-table table:where(:not(.has-text-color)) * {
+	border-color: inherit;
+}
+
 .wp-block-table.is-style-stripes tbody tr:nth-child(odd) {
 	background: #dcd7ca;
 }