Fix typo

Author: GeorgDangl

README.md

@@ -1456,7 +1456,7 @@ BCF is suitable for selecting a few components. A huge list of selected componen
 [coloring.json](Schemas_draft-03/Collaboration/Viewpoint/coloring.json)
 
 #####Optimization rules
-BCF is suitable for coloring on a few components. A huge list of components causes poor performance. All clients should follow this rule:
+BCF is suitable for coloring a few components. A huge list of components causes poor performance. All clients should follow this rule:
 - If the size of colored components is huge (approximately 1000 components), alert the user and give him the opportunity to modify the coloring.
 
 The color is given in ARGB format. Colors are represented as 6 or 8 hexadecimal digits. If 8 digits are present, the first two represent the alpha (transparency) channel. For example, `40E0D0` would be the color <span style="color:#40E0D0;";>Turquoise</span>. [More information about the color format can be found on Wikipedia.](https://en.wikipedia.org/wiki/RGBA_color_space)