snapshot of https://github.com/zulip/zulip.git @ 48c69911c7dd4e03b20552eb3bd77ad8151c1357 (2026-09-15)

zerver/lib/stream_color.py

@@ -0,0 +1,56 @@
+STREAM_ASSIGNMENT_COLORS = [
+    "#76ce90",
+    "#fae589",
+    "#a6c7e5",
+    "#e79ab5",
+    "#bfd56f",
+    "#f4ae55",
+    "#b0a5fd",
+    "#addfe5",
+    "#f5ce6e",
+    "#c2726a",
+    "#94c849",
+    "#bd86e5",
+    "#ee7e4a",
+    "#a6dcbf",
+    "#95a5fd",
+    "#53a063",
+    "#9987e1",
+    "#e4523d",
+    "#c2c2c2",
+    "#4f8de4",
+    "#c6a8ad",
+    "#e7cc4d",
+    "#c8bebf",
+    "#a47462",
+]
+
+
+def pick_colors(
+    used_colors: set[str], color_map: dict[int, str], recipient_ids: list[int]
+) -> dict[int, str]:
+    used_colors = set(used_colors)
+    recipient_ids = sorted(recipient_ids)
+    result = {}
+
+    other_recipient_ids = []
+    for recipient_id in recipient_ids:
+        if recipient_id in color_map:
+            color = color_map[recipient_id]
+            result[recipient_id] = color
+            used_colors.add(color)
+        else:
+            other_recipient_ids.append(recipient_id)
+
+    available_colors = [s for s in STREAM_ASSIGNMENT_COLORS if s not in used_colors]
+
+    for i, recipient_id in enumerate(other_recipient_ids):
+        if i < len(available_colors):
+            color = available_colors[i]
+        else:
+            # We have to start reusing old colors, and we use recipient_id
+            # to choose the color.
+            color = STREAM_ASSIGNMENT_COLORS[recipient_id % len(STREAM_ASSIGNMENT_COLORS)]
+        result[recipient_id] = color
+
+    return result