diff -r ad9170e4838b trytond/trytond/ir/ui/tree.rnc
--- a/trytond/trytond/ir/ui/tree.rnc	Tue Aug 30 14:38:04 2016 +0200
+++ b/trytond/trytond/ir/ui/tree.rnc	Mon Feb 13 11:11:10 2017 +0100
@@ -9,6 +9,7 @@
 attlist.tree &= attribute on_write { text }?
 attlist.tree &= attribute editable { "top" | "bottom" }?
 attlist.tree &= attribute sequence { text }?
+attlist.tree &= attribute colors { text }?
 attlist.tree &=
   [ a:defaultValue = "0" ] attribute keyword_open { "0" | "1" }?
 attlist.tree &=
@@ -62,6 +63,7 @@
 attlist.field &= attribute string { text }?
 attlist.field &= [a:defaultValue = "1"] attribute factor { text }?
 attlist.field &= attribute filename { text }?
+attlist.field &= attribute view_ids { text }?
 prefix = element prefix { attlist.affix, empty }
 suffix = element suffix { attlist.affix, empty }
 attlist.affix &= attribute string { text }?
 diff -r ad9170e4838b trytond/trytond/ir/ui/tree.rng
 --- a/trytond/trytond/ir/ui/tree.rng	Tue Aug 30 14:38:04 2016 +0200
 +++ b/trytond/trytond/ir/ui/tree.rng	Mon Feb 13 11:11:10 2017 +0100
 @@ -38,6 +38,11 @@
    </define>
    <define name="attlist.tree" combine="interleave">
      <optional>
 +      <attribute name="colors"/>
 +    </optional>
 +  </define>
 +  <define name="attlist.tree" combine="interleave">
 +    <optional>
        <attribute name="keyword_open" a:defaultValue="0">
          <choice>
            <value>0</value>
 @@ -198,6 +203,11 @@
        <attribute name="filename"/>
      </optional>
    </define>
 +  <define name="attlist.field" combine="interleave">
 +    <optional>
 +      <attribute name="view_ids"/>
 +    </optional>
 +  </define>
    <define name="prefix">
      <element name="prefix">
        <ref name="attlist.affix"/>
diff -r ad9170e4838b trytond/trytond/ir/ui/view.py
--- a/trytond/trytond/ir/ui/view.py     Tue Aug 30 14:38:04 2016 +0200
+++ b/trytond/trytond/ir/ui/view.py     Mon Feb 13 11:21:02 2017 +0100
@@ -155,7 +155,7 @@
             }

             def encode(element):
-                for attr in ('states', 'domain', 'spell'):
+                for attr in ('states', 'domain', 'spell', 'colors'):
                     if element.get(attr):
                         try:
                             value = PYSONDecoder().decode(element.get(attr))
diff -r b1c807b558e9 trytond/trytond/model/modelview.py
--- a/trytond/trytond/model/modelview.py	Wed Sep 28 08:14:45 2016 +0200
+++ b/trytond/trytond/model/modelview.py	Wed Sep 28 08:19:23 2016 +0200
@@ -488,59 +488,67 @@
             fields_attrs = {}
         else:
             fields_attrs = copy.deepcopy(fields_attrs)
-        childs = True

-        if element.tag in ('field', 'label', 'separator', 'group', 'suffix',
-                'prefix'):
+        def set_view_ids(element):
+            view_ids = []
+            if element.get('view_ids'):
+                for view_id in element.get('view_ids').split(','):
+                    try:
+                        view_ids.append(int(view_id))
+                    except ValueError:
+                        view_ids.append(ModelData.get_id(*view_id.split('.')))
+                element.attrib['view_ids'] = ','.join(map(str, view_ids))
+            return view_ids
+
+        def get_relation(field):
+            if hasattr(field, 'model_name'):
+                return field.model_name
+            elif hasattr(field, 'get_target'):
+                return field.get_target().__name__
+
+        def get_views(relation, view_ids, mode):
+            Relation = pool.get(relation)
+            views = {}
+            if field._type in ['one2many', 'many2many']:
+                # Prefetch only the first view to prevent infinite loop
+                if view_ids:
+                    for view_id in view_ids:
+                        view = Relation.fields_view_get(view_id=view_id)
+                        views[str(view_id)] = view
+                        break
+                else:
+                    for view_type in mode:
+                        views[view_type] = (
+                            Relation.fields_view_get(view_type=view_type))
+                        break
+            return views
+
+        for attr in ('name', 'icon'):
+            if not element.get(attr):
+                continue
+            fields_attrs.setdefault(element.get(attr), {})
+
+        if element.tag == 'field' and type in ['tree', 'form']:
             for attr in ('name', 'icon'):
-                if element.get(attr):
-                    fields_attrs.setdefault(element.get(attr), {})
-                    if type != 'form':
-                        continue
-                    try:
-                        field = cls._fields[element.get(attr)]
-                        if hasattr(field, 'model_name'):
-                            relation = field.model_name
-                        else:
-                            relation = field.get_target().__name__
-                    except Exception:
-                        relation = False
-                    if relation and element.tag == 'field':
-                        childs = False
-                        views = {}
-                        mode = (element.attrib.pop('mode', None)
-                            or 'tree,form').split(',')
-                        view_ids = []
-                        if element.get('view_ids'):
-                            for view_id in element.get('view_ids').split(','):
-                                try:
-                                    view_ids.append(int(view_id))
-                                except ValueError:
-                                    view_ids.append(ModelData.get_id(
-                                            *view_id.split('.')))
-                        Relation = pool.get(relation)
-                        if (not len(element)
-                                and type == 'form'
-                                and field._type in ('one2many', 'many2many')):
-                            # Prefetch only the first view to prevent infinite
-                            # loop
-                            if view_ids:
-                                for view_id in view_ids:
-                                    view = Relation.fields_view_get(
-                                        view_id=view_id)
-                                    views[str(view_id)] = view
-                                    break
-                            else:
-                                for view_type in mode:
-                                    views[view_type] = \
-                                        Relation.fields_view_get(
-                                            view_type=view_type)
-                                    break
-                        element.attrib['mode'] = ','.join(mode)
-                        element.attrib['view_ids'] = ','.join(
-                            map(str, view_ids))
-                        fields_attrs[element.get(attr)].setdefault('views', {}
-                            ).update(views)
+                fname = element.get(attr)
+                if not fname:
+                    continue
+                view_ids = set_view_ids(element)
+                if type != 'form':
+                    continue
+                try:
+                    field = cls._fields[fname]
+                    relation = get_relation(field)
+                except:
+                    relation = False
+                if not relation:
+                    continue
+                mode = (
+                    element.attrib.pop('mode', None) or 'tree,form').split(',')
+                views = get_views(relation, view_ids, mode)
+                element.attrib['mode'] = ','.join(mode)
+                fields_attrs[fname].setdefault('views', {}).update(views)
+
             if type == 'tree' and element.get('name') in fields_width:
                 element.set('width', str(fields_width[element.get('name')]))

@@ -588,10 +593,9 @@
                 if element.get(attr):
                     fields_attrs.setdefault(element.get(attr), {})

-        if childs:
-            for field in element:
-                fields_attrs = cls.__view_look_dom(field, type,
-                    fields_width=fields_width, fields_attrs=fields_attrs)
+        for field in element:
+            fields_attrs = cls.__view_look_dom(field, type,
+                fields_width=fields_width, fields_attrs=fields_attrs)
         return fields_attrs

     @staticmethod