diff --git a/CHANGELOG b/CHANGELOG
index a66f566123..c467730688 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,4 @@
+* Remove default colors on graph and calendar
 * Add model, record and records attributes on Wizard
 * Check read access of wizard records
 * Add cached_property in tools
diff --git a/trytond/ir/ui/calendar.rnc b/trytond/ir/ui/calendar.rnc
index 1af4fb3f78..d66efa0b15 100644
--- a/trytond/ir/ui/calendar.rnc
+++ b/trytond/ir/ui/calendar.rnc
@@ -10,10 +10,8 @@ attlist.calendar &=
       | "week"
       | "month" }?
 attlist.calendar &= [a:defaultValue = "1" ] attribute editable { "0" | "1" }?
-attlist.calendar &=
-   [ a:defaultValue = "black" ] attribute color { text }?
-attlist.calendar &=
-   [ a:defaultValue = "lightblue" ] attribute background_color { text }?
+attlist.calendar &= attribute color { text }?
+attlist.calendar &= attribute background_color { text }?
 attlist.calendar &=
   attribute width { text }?
 attlist.calendar &=
diff --git a/trytond/ir/ui/calendar.rng b/trytond/ir/ui/calendar.rng
index 0e5b31d40a..ef8f90d002 100644
--- a/trytond/ir/ui/calendar.rng
+++ b/trytond/ir/ui/calendar.rng
@@ -49,7 +49,7 @@
   </define>
   <define name="attlist.calendar" combine="interleave">
     <optional>
-      <attribute a:defaultValue="black">
+      <attribute>
         <name ns="">color</name>
         <text/>
       </attribute>
@@ -57,7 +57,7 @@
   </define>
   <define name="attlist.calendar" combine="interleave">
     <optional>
-      <attribute a:defaultValue="lightblue">
+      <attribute>
         <name ns="">background_color</name>
         <text/>
       </attribute>
diff --git a/trytond/ir/ui/graph.rnc b/trytond/ir/ui/graph.rnc
index aca2221198..6a4f493895 100644
--- a/trytond/ir/ui/graph.rnc
+++ b/trytond/ir/ui/graph.rnc
@@ -4,9 +4,8 @@ graph = element graph { attlist.graph, x*, y* }
 attlist.graph &=
   [ a:defaultValue = "vbar" ]
   attribute type { "vbar" | "hbar" | "line" | "pie" }?
-attlist.graph &=
-  [ a:defaultValue = "#f5f5f5" ] attribute background { text }?
-attlist.graph &= [ a:defaultValue = "blue" ] attribute color { text }?
+attlist.graph &= attribute background { text }?
+attlist.graph &= attribute color { text }?
 attlist.graph &=
   [ a:defaultValue = "1" ] attribute legend { "0" | "1" }?
 x = element x { attlist.x, field }
diff --git a/trytond/ir/ui/graph.rng b/trytond/ir/ui/graph.rng
index 073a38b69c..f5d1e4fff2 100644
--- a/trytond/ir/ui/graph.rng
+++ b/trytond/ir/ui/graph.rng
@@ -28,7 +28,7 @@
   </define>
   <define name="attlist.graph" combine="interleave">
     <optional>
-      <attribute a:defaultValue="#f5f5f5">
+      <attribute>
         <name ns="">background</name>
         <text/>
       </attribute>
@@ -36,7 +36,7 @@
   </define>
   <define name="attlist.graph" combine="interleave">
     <optional>
-      <attribute a:defaultValue="blue">
+      <attribute>
         <name ns="">color</name>
         <text/>
       </attribute>