diff --git a/src/Text-Core/TextColor.class.st b/src/Text-Core/TextColor.class.st
index 96b15528c99..6556b253293 100644
--- a/src/Text-Core/TextColor.class.st
+++ b/src/Text-Core/TextColor.class.st
@@ -99,6 +99,7 @@ TextColor >> color: aColor [
 
 { #category : #scanning }
 TextColor >> dominates: other [
+"Only one color attribute on a same portion of text."
 	^ other class == self class
 ]
 
diff --git a/src/Text-Tests/TextColorTest.class.st b/src/Text-Tests/TextColorTest.class.st
new file mode 100644
index 00000000000..1fd06137fb1
--- /dev/null
+++ b/src/Text-Tests/TextColorTest.class.st
@@ -0,0 +1,35 @@
+Class {
+	#name : #TextColorTest,
+	#superclass : #TestCase,
+	#category : #'Text-Tests-Base'
+}
+
+{ #category : #tests }
+TextColorTest >> testColor [
+	| textColor |
+	textColor := TextColor new color: Color red.
+	self assert: textColor color equals: Color red.
+	self assert: textColor asColor equals: Color red.
+	
+]
+
+{ #category : #tests }
+TextColorTest >> testDominates [
+	| text |
+	self assert: (TextColor red dominates: TextColor yellow).
+	self assert: (TextColor red dominates: TextColor red).
+	self deny: (TextColor red dominates: TextEmphasis bold).
+	self deny: (TextColor red dominates: TextFontChange font2).
+	"In action"
+	text := 'Pharo is cool' asText.
+	text addAttribute: TextColor red.
+	"Only one color at time, the last added color win"
+	text addAttribute: TextColor yellow.
+	self assert: (text attributesAt: 1) size equals: 1.
+	self assert: (text attributesAt: 1) first color equals: Color yellow.
+	"Can be both colored and bold"
+	text addAttribute: TextEmphasis bold.
+	self assert: (text attributesAt: 1) size equals: 2.
+	self assert: (text attributesAt: 1) first color equals: Color yellow.
+	self assert: (text attributesAt: 2) second emphasisCode equals: 1
+]
diff --git a/src/Text-Tests/TextStreamTest.class.st b/src/Text-Tests/TextStreamTest.class.st
index 702999d165a..87622173881 100644
--- a/src/Text-Tests/TextStreamTest.class.st
+++ b/src/Text-Tests/TextStreamTest.class.st
@@ -15,6 +15,20 @@ TextStreamTest >> setUp [
 	stream := TextStream on: (Text new:100)
 ]
 
+{ #category : #test }
+TextStreamTest >> testApplyAttributeBeginningAt [
+	| attributes |
+	stream nextPutAll: 'Pharo is cool'.
+	stream applyAttribute:  TextEmphasis underlined beginningAt: 10.
+	1 to: 9 do: [ :index |
+		attributes := stream contents runs at: index.
+		self assertEmpty: attributes].	
+	10 to: 14 do: [ :index |
+		attributes := stream contents runs at: index.
+		self assert: attributes isArray.
+		self assert: attributes first emphasisCode equals: 4].
+]
+
 { #category : #test }
 TextStreamTest >> testNextPutAll [
 	stream