maybe you can use another method that I usually use
 \definefontsynonym[PalatinoRoman][name:palatinolinotypebold][features=default]\definefont[TitleFont][PalatinoRoman sa 1]...> From: schuster.wolfgang@gmail.com
> Date: Sun, 14 Apr 2013 23:42:16 +0200
> To: ntg-context@ntg.nl
> Subject: Re: [NTG-context] Different fonts for titles
> 
> 
> Am 14.04.2013 um 14:34 schrieb H. Özoguz <h.oezoguz@mmnetz.de>:
> 
> > Hoping for some hints .... :)
> 
> What you’re looking for is the \definefont command, in one way a low level method to access a font
> but also a usefull command to create styles for headings etc.
> 
> 
> Let me start with the following example:
> 
>   \definefont[Test][texgyrepagellaregular at 12pt]
> 
>   \starttext
>   \Test VA ffl
>   \stoptext
> 
> What I do here is to create the new command \Test which loads the file “texgrepagellaregular”
> at a size 12pt. With the optional prefix on front of the font name you can specify the search method,
> context provides the three different methods a) file b) name and c) spec.
> 
>   a) \definefont[Test][file:texgyrepagellaregular]
>   b) \definefont[Test][name:texgyrepagellaregular]
>   c) \definefont[Test][spec:texgyrepagella-normal-normal]
> 
> 
> Instead of a fixed size for the font you can also use a relative size which depends on the bodyfont.
> 
>   \definefont[Test][texgyrepagellaregular sa 1]
> 
>   \starttext
>   \Test VA ffl \switchtobodyfont[20pt]\Test VA ffl
>   \stoptext
> 
> When you use “sa XX” as argument for the size your font scales also when you change the bodyfont
> in the middle of the document.
> 
> 
> One problem of the definitions above is that kerning, ligatures etc. aren’t activated for the font
> because no feature isn’t applied. To apply a feature set you have to use a different method than
> the one which is used in a typescript because \definefont has no feature-key. What you have to
> do to apply the set is to append it after the name name and separate both with a asterisks.
> 
>   \definefont[Test][texgyrepagellaregular*default sa 1]
> 
>   \starttext
>   \Test VA ffl
>   \stoptext
> 
> 
> Instead of the real name of a file you can also use a symbolic name from a typescript.
> 
>   \definefont[Test][SansBold sa 1]
> 
>   \starttext
>   \Test VA ffl
>   \stoptext
> 
> In this example I used the bold version of the sans style for my \Test font, in this case
> you don’t have to add the name of a feature because it has been already set in the typescript.
> 
> 
> A complete example in a document could be look like this:
> 
> \definetypeface[mainface][rm][specserif][Antykwa Poltawskiego]
> \definetypeface[mainface][ss][specsans] [Iwona]
> 
> \definefont[ChapterStyle][SansBold sa 3]
> 
> \setuphead[chapter][style=ChapterStyle]
> 
> \setupbodyfont[mainface]
> 
> \starttext
> 
> \chapter{Knuth}
> 
> \input knuth
> 
> \stoptext
> 
> 
> Wolfgang
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