diff --git a/.github/workflows/run-nala-default.yml b/.github/workflows/run-nala-default.yml
index ddf2f9dd4..85dc8826f 100644
--- a/.github/workflows/run-nala-default.yml
+++ b/.github/workflows/run-nala-default.yml
@@ -17,17 +17,25 @@ permissions:
 
 jobs:
   run-nala-tests:
-    name: Running Nala E2E UI Tests
+    name: Running Nala E2E UI Tests (${{ matrix.lane_id }})
     runs-on: ubuntu-latest
     timeout-minutes: 30
     strategy:
-      # Don't cancel the other shards when one fails — we want the full picture.
+      # Don't cancel the other lanes when one fails — we want the full picture.
       fail-fast: false
       matrix:
-        node-version: [24.x]
-        # Split the suite across parallel runner jobs. Playwright's --shard
-        # deterministically partitions tests, so 4 shards ≈ 4x throughput.
-        shard: [1, 2, 3, 4]
+        # Lanes run as parallel runner jobs. The non-color suite is split across
+        # 4 shards (Playwright's --shard deterministically partitions tests). The
+        # heavy color-shared blocks are pulled OUT of the shards (each shard lane
+        # excludes @color) and run in their own serial lane (workers=1) so they
+        # never cluster on one shard and starve each other's decoration — the
+        # cause of the recurring color-block waitReady timeouts.
+        include:
+          - { lane_id: shard1, node: 24.x, shard: '1/4', exclude: '@color', grep: '', workers: '' }
+          - { lane_id: shard2, node: 24.x, shard: '2/4', exclude: '@color', grep: '', workers: '' }
+          - { lane_id: shard3, node: 24.x, shard: '3/4', exclude: '@color', grep: '', workers: '' }
+          - { lane_id: shard4, node: 24.x, shard: '4/4', exclude: '@color', grep: '', workers: '' }
+          - { lane_id: color, node: 24.x, shard: '', exclude: '', grep: '@color', workers: '1' }
 
     steps:
       - name: Checkout repository
@@ -35,10 +43,10 @@ jobs:
         with:
           fetch-depth: 2
 
-      - name: Set up Node.js ${{ matrix.node-version }}
+      - name: Set up Node.js ${{ matrix.node }}
         uses: actions/setup-node@cdca7365b2dadb8aad0a33bc7601856ffabcc48e
         with:
-          node-version: ${{ matrix.node-version }}
+          node-version: ${{ matrix.node }}
 
       - name: Cache node_modules
         uses: actions/cache@v4
@@ -46,13 +54,13 @@ jobs:
           path: |
             ~/.npm
             **/node_modules
-          key: npm-${{ runner.os }}-${{ matrix.node-version }}-${{ hashFiles('**/package-lock.json') }}
+          key: npm-${{ runner.os }}-${{ matrix.node }}-${{ hashFiles('**/package-lock.json') }}
 
       - name: Cache Playwright browsers
         uses: actions/cache@v4
         with:
           path: ~/.cache/ms-playwright
-          key: ms-playwright-${{ runner.os }}-${{ matrix.node-version }}-chromium
+          key: ms-playwright-${{ runner.os }}-${{ matrix.node }}-chromium
 
       - name: Install dependencies
         run: npm ci --no-fund --prefer-offline
@@ -75,7 +83,12 @@ jobs:
           # PR gate: full cross-browser matrix, sharded across parallel jobs
           # so wall-clock stays low even with all three browsers.
           NALA_PROJECTS: --project=express-live-chromium --project=express-live-firefox --project=express-live-webkit
-          SHARD: ${{ matrix.shard }}/4
+          # Sharded lanes: SHARD set + exclude @color. Color lane: no shard,
+          # grep only @color, workers=1 (serial).
+          SHARD: ${{ matrix.shard }}
+          NALA_EXTRA_GREP_INVERT: ${{ matrix.exclude }}
+          NALA_GREP: ${{ matrix.grep }}
+          NALA_WORKERS: ${{ matrix.workers }}
           labels: ${{ join(github.event.pull_request.labels.*.name, ' ') }}
           branch: ${{ github.event.pull_request.head.ref }}
           repoName: ${{ github.repository }}
@@ -92,7 +105,7 @@ jobs:
         if: always()
         uses: actions/upload-artifact@v4
         with:
-          name: nala-test-results-${{ github.run_number }}-shard${{ matrix.shard }}
+          name: nala-test-results-${{ github.run_number }}-${{ matrix.lane_id }}
           path: |
             test-results/
             test-html-results/
diff --git a/nala/utils/pr.run.sh b/nala/utils/pr.run.sh
index 6f966da35..f7ff72922 100755
--- a/nala/utils/pr.run.sh
+++ b/nala/utils/pr.run.sh
@@ -3,8 +3,14 @@ set -e
 
 TAGS=""
 REPORTER=""
-EXCLUDE_TAGS="--grep-invert nopr"
-EXCLUDE_MONITORING="--grep-invert @monitoring"
+# Single combined --grep-invert: Playwright applies only the LAST --grep-invert
+# flag, so every exclusion must live in one regex. nopr = never run in PR/CI;
+# @monitoring = synthetic monitors. Sharded lanes additionally pass
+# NALA_EXTRA_GREP_INVERT="@color" to hand the heavy color blocks off to their
+# own serial lane (they starve each other's decoration when clustered).
+GREP_INVERT="nopr|@monitoring"
+[[ -n "$NALA_EXTRA_GREP_INVERT" ]] && GREP_INVERT="${GREP_INVERT}|${NALA_EXTRA_GREP_INVERT}"
+EXCLUDE_TAGS="--grep-invert ${GREP_INVERT}"
 EXIT_STATUS=0
 
 echo "GITHUB_REF: $GITHUB_REF"
@@ -74,13 +80,18 @@ done
 # Remove first pipe if TAGS not empty
 [[ ! -z "$TAGS" ]] && TAGS="${TAGS:1}" && TAGS="-g $TAGS"
 
+# Positive grep. A lane override (NALA_GREP, e.g. "@color" for the serial color
+# lane) takes precedence over PR-label tags.
+GREP_ARG="$TAGS"
+[[ -n "$NALA_GREP" ]] && GREP_ARG="-g $NALA_GREP"
+
 # Reporter (override if provided)
 REPORTER=$reporter
 [[ ! -z "$REPORTER" ]] && REPORTER="--reporter $REPORTER"
 
 echo "Running Nala on branch: $FEATURE_BRANCH"
 echo "Tags: ${TAGS:-"No @tags or annotations on this PR"}"
-echo "Run Command: npx playwright test ${TAGS} ${EXCLUDE_TAGS} ${EXCLUDE_MONITORING} ${REPORTER}"
+echo "Run Command: npx playwright test ${GREP_ARG} ${EXCLUDE_TAGS} ${REPORTER}"
 echo -e "\n"
 echo "*******************************"
 
@@ -102,10 +113,11 @@ SHARD_ARG=""
 
 # Run Playwright tests
 echo "*** Running tests on projects: ${PROJECTS} ${SHARD_ARG:-"(no shard)"} ***"
-echo "*** Excluding monitoring tests (@monitoring) ***"
+echo "*** grep-invert: ${GREP_INVERT} ***"
+[[ -n "$NALA_GREP" ]] && echo "*** grep (include only): ${NALA_GREP} — workers: ${NALA_WORKERS:-config default} ***"
 npx playwright test \
   --config=./playwright.config.cjs \
-  ${TAGS} ${EXCLUDE_TAGS} ${EXCLUDE_MONITORING} ${REPORTER} \
+  ${GREP_ARG} ${EXCLUDE_TAGS} ${REPORTER} \
   ${PROJECTS} ${SHARD_ARG} || EXIT_STATUS=$?
 
 # Exit status