[FIX] color serialization to be in a full hex format

Author: ilaif

src/structurizr/view/color.py

@@ -0,0 +1,17 @@
+import pydantic.color
+
+
+class Color(pydantic.color.Color):
+    def as_hex(self) -> str:
+        """
+        Hex string representing the color
+        """
+        values = [pydantic.color.float_to_255(c) for c in self._rgba[:3]]
+        if self._rgba.alpha is not None:
+            values.append(pydantic.color.float_to_255(self._rgba.alpha))
+
+        as_hex = "".join(f"{v:02x}" for v in values)
+        return "#" + as_hex
+
+    def __str__(self) -> str:
+        return self.as_hex()

src/structurizr/view/element_style.py

@@ -19,7 +19,7 @@
 from typing import Optional
 
 from pydantic import Field
-from pydantic.color import Color
+from .color import Color
 
 from ..abstract_base import AbstractBase
 from ..base_model import BaseModel

src/structurizr/view/relationship_style.py

@@ -19,7 +19,7 @@
 from typing import Optional
 
 from pydantic import Field
-from pydantic.color import Color
+from .color import Color
 
 from ..abstract_base import AbstractBase
 from ..base_model import BaseModel