XSLT help pls!

my xml file looks like this
<Item>
<ItemID>1</ItemID>
<Name>Golf Shirt</Name>
<category>Apparel</category>
<ItemAttributes><CatalogNumber>F4123</CatalogNumber>
<Color>White/Navy</Color>
</ItemAttributes>
<ItemAttributes><CatalogNumber>F4123</CatalogNumber>
<Color>Black</Color>
</ItemAttributes>

Now i want my o/p sth like this
<Name>Golf Shirt</Name>
<category>Apparel</category>
<CatalogNumber>F4123</CatalogNumber>
<name>Color:White/Navy</name>
<name>Color:Black</name>

My following code is giving me the output
<Name>Golf Shirt</Name>
<category>Apparel</category>
<CatalogNumber>F4123</CatalogNumber>
<name>Color:White/Navy</name>
<CatalogNumber>F4123</CatalogNumber>
<name>Color:Black</name>

I don't want the <CatalogNumber> to repeat

Howcan i do that??
any help would be greatly appreciated!! Thanks

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<?xml version="1.0" encoding="UTF-8" ?>
<xsl:transform version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<xsl:for-each select="//Item">
<name><xsl:value-of select="Name"/></name>
<category-name><xsl:value-of select="category"/></category-name>
<xsl:for-each select="ItemAttributes">
<catalog-number><xsl:value-of select="CatalogNumber"/></catalog-number>
<name>
<xsl:if test="Color != ''">Color: <xsl:value-of select="Color"/ >
</name>
</xsl:for-each>
</xsl:for-each>

Why is it repeated in the data in the first place?