Sealant advice - steel window/wood frame

[llama]

I need to reseal the gap between a powder coated steel window frame and the painted wood frame it sits in. The gap is just 2-3mm in some places opening out to 10mm in a couple of areas.

I realise there's a massive array of silicones and acrylic sealants but what's the best thing to use in this instance?

I was hoping to avoid silicone as dust and grit seems to stick to it but if it's the best thing to use I'll go with it. Alternatively, if acrylic sealant is best, should it be painted?

Thanks in advance.