sync color4f with docs

NOTRY=true
TBR=brianosman@google.com

Docs-Preview: https://skia.org/?cl=156300
Bug: skia:
Change-Id: I7e4f8079b5c30dfaf08cf719a5d90a0eff64906b
Reviewed-on: https://skia-review.googlesource.com/156300
Commit-Queue: Cary Clark <caryclark@skia.org>
Auto-Submit: Cary Clark <caryclark@skia.org>
Reviewed-by: Cary Clark <caryclark@skia.org>
diff --git a/docs/SkColor4f_Reference.bmh b/docs/SkColor4f_Reference.bmh
index 251145d..184dc27 100644
--- a/docs/SkColor4f_Reference.bmh
+++ b/docs/SkColor4f_Reference.bmh
@@ -284,13 +284,43 @@
 
 # ------------------------------------------------------------------------------
 
-#Method SkPM4f premul() const
+#Method SkColor4f premul() const
 #In Utility
-#Line # returns Premultiplied color; internal use only ##
+#Line # returns Premultiplied color ##
+
+Returns SkColor4f with all components premultiplied by Alpha.
+
+#Return Premultiplied color ##
+
+#NoExample
+##
+
+#SeeAlso unpremul
+
+#Method ##
+
+#Method SkColor4f unpremul() const
+#In Utility
+#Line # returns Unpremultiplied color ##
+
+Returns SkColor4f with all components independent of Alpha.
+
+#Return Unpremultiplied color ##
+
+#NoExample
+##
+
+#SeeAlso premul
+
+#Method ##
+
+#Method SkPM4f toPM4f() const
+#Line # is for internal use only ##
+
 #Private
 Internal use only.
 ##
-#Return Premultiplied color ##
+#Return premultiplied color ##
 #Method ##
 
 #Struct SkColor4f ##
diff --git a/site/user/api/SkColor4f_Reference.md b/site/user/api/SkColor4f_Reference.md
index 4e2c59c..badd38c 100644
--- a/site/user/api/SkColor4f_Reference.md
+++ b/site/user/api/SkColor4f_Reference.md
@@ -97,12 +97,20 @@
   </tr>
   <tr>
     <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkColor4f_premul'>premul</a></td>
-    <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns <a href='undocumented#Premultiply'>Premultiplied</a> color; internal use only</td>
+    <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns <a href='undocumented#Premultiply'>Premultiplied</a> color</td>
   </tr>
   <tr style='background-color: #f0f0f0; '>
+    <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkColor4f_toPM4f'>toPM4f</a></td>
+    <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>is for internal use only</td>
+  </tr>
+  <tr>
     <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkColor4f_toSkColor'>toSkColor</a></td>
     <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns closest <a href='SkColor_Reference#Color'>Color</a></td>
   </tr>
+  <tr style='background-color: #f0f0f0; '>
+    <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkColor4f_unpremul'>unpremul</a></td>
+    <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns <a href='undocumented#Unpremultiply'>Unpremultiplied</a> color</td>
+  </tr>
   <tr>
     <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkColor4f_vec'>vec</a></td>
     <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns array of components</td>
@@ -422,13 +430,51 @@
 ## premul
 
 <pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
-<a href='#SkPM4f'>SkPM4f</a> <a href='#SkColor4f_premul'>premul</a>() const
+<a href='#SkColor4f'>SkColor4f</a> <a href='#SkColor4f_premul'>premul</a>() const
 </pre>
 
+Returns <a href='#SkColor4f'>SkColor4f</a> with all components premultiplied by <a href='SkColor_Reference#Alpha'>Alpha</a>.
+
 ### Return Value
 
 <a href='undocumented#Premultiply'>Premultiplied</a> color
 
+### See Also
+
+<a href='#SkColor4f_unpremul'>unpremul</a>
+
+---
+
+<a name='SkColor4f_unpremul'></a>
+## unpremul
+
+<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
+<a href='#SkColor4f'>SkColor4f</a> <a href='#SkColor4f_unpremul'>unpremul</a>() const
+</pre>
+
+Returns <a href='#SkColor4f'>SkColor4f</a> with all components independent of <a href='SkColor_Reference#Alpha'>Alpha</a>.
+
+### Return Value
+
+<a href='undocumented#Unpremultiply'>Unpremultiplied</a> color
+
+### See Also
+
+<a href='#SkColor4f_premul'>premul</a>
+
+---
+
+<a name='SkColor4f_toPM4f'></a>
+## toPM4f
+
+<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
+<a href='#SkPM4f'>SkPM4f</a> <a href='#SkColor4f_toPM4f'>toPM4f</a>() const
+</pre>
+
+### Return Value
+
+premultiplied color
+
 ---
 
 # <a name='SkPM4f'>Struct SkPM4f</a>