diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index a95d1fcc7..a099245d8 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -13,6 +13,13 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: ${{ github.event_name == 'pull_request' }}
 
+# Pin the Docker build-volume name so CI's bind-backed "mx-build" volume
+# (created per-job below) is the one the Makefile actually mounts. Without
+# this the Makefile computes a CURDIR-hashed name (for worktree isolation)
+# that doesn't match the pre-created volume.
+env:
+  DOCKER_VOLUME: mx-build
+
 jobs:
   linux-gen:
     name: Linux (generator gates)
diff --git a/Makefile b/Makefile
index f97324315..158286bc6 100644
--- a/Makefile
+++ b/Makefile
@@ -39,8 +39,9 @@ DOCKER_CACHE := --cache-from type=gha --cache-to type=gha,mode=max
 endif
 
 # Docker SDK image + build volume. Incremental state persists across runs.
+# Volume name includes a path hash so parallel worktrees get isolated caches.
 DOCKER_IMAGE  := mx-sdk
-DOCKER_VOLUME := mx-build
+DOCKER_VOLUME ?= mx-build-$(shell printf '%s' '$(CURDIR)' | md5sum 2>/dev/null | cut -c1-8 || printf '%s' '$(CURDIR)' | md5 -q | cut -c1-8)
 DOCKER_STAMP  := $(BUILD_ROOT)/.docker-image-stamp
 
 # Prevent root-owned files on Linux.
diff --git a/src/private/mx/impl/DirectionReader.cpp b/src/private/mx/impl/DirectionReader.cpp
index ebf04df26..c94f71beb 100644
--- a/src/private/mx/impl/DirectionReader.cpp
+++ b/src/private/mx/impl/DirectionReader.cpp
@@ -416,7 +416,11 @@ void DirectionReader::parseWords(const core::DirectionType &directionType)
         api::WordsData outWords;
         outWords.text = wordEl.value();
         outWords.positionData = getPositionData(wordEl);
-        outWords.colorData = getColor(wordEl);
+        outWords.isColorSpecified = wordEl.color().has_value();
+        if (outWords.isColorSpecified)
+        {
+            outWords.colorData = getColor(wordEl);
+        }
         outWords.fontData = getFontData(wordEl);
         if (wordEl.enclosure().has_value())
         {