diff --git a/CONTRACT.md b/CONTRACT.md
index 56f4880..9116648 100644
--- a/CONTRACT.md
+++ b/CONTRACT.md
@@ -8,10 +8,9 @@ Hand-maintained for Phase 6; the `## Inputs` table is generated from
 | Canonical | Aliases (deprecated) | Payload | Effect |
 |---|---|---|---|
 | `data.influent` | `influent`, `setInfluent` | `{ F: number, C: number[13] }` — either field optional | Replaces influent flow and/or the 13-species concentration vector. Triggers `output-changed`, re-emits the 3-stream Fluent envelope. |
+| `child.register` | `registerChild` | `string` — the child node's Node-RED id | Resolves the child via `RED.nodes.getNode` and registers it through `childRegistrationUtils` at the supplied `msg.positionVsParent`. |
 
 Aliases log a one-time deprecation warning the first time they fire.
-Plumbing topics (`child.register`) are handled by the BaseNodeAdapter and
-not listed here.
 
 ## Outputs
 
diff --git a/settler.html b/settler.html
index 703a588..4927c9b 100644
--- a/settler.html
+++ b/settler.html
@@ -3,7 +3,7 @@
 <script type="text/javascript">
   RED.nodes.registerType("settler", {
     category: "EVOLV",
-    color: "#e4a363",
+    color: "#50a8d9",
     defaults: {
       name: { value: "" },
       processOutputFormat: { value: "process" },