Tim Gasjer Fox Gear Trentino

This is because his name is Tim Gajser

National colors?

The Slovenian national color is green, and the flag is red, white, and blue.

Maybe it's a just preview for 2019 gear?

The red/yellow is kinda his "signature color" combo. Just like cairoli always wears something flo yellow.

This was a custom kit, as Trentino is like a home GP for him (Closest one to Slovenia). And yeah, the Yellow/Red is his signature style, he had a similar color combo for the SMX-Cup couple years ago (there was also a red/yellow custom kit from Shift, when he clinched the World MX2 title).
The kit from Trentino also had a green stripe in front symbolising Slovenia.

He always wore yellow gear, because his father had a tragic accident in which he fataly injured his 2 or 3 year old son... His father brought it up in a lot of interviews. His son that died that day was Tim's brother, and he was wearing yellow clothes when he passed. That's why it's his "sigature" color, that's why you always see his father wearing full yellow, and all his "offical" merchendise is mostly in yellow. The red is just representing HRC. When he was racing EMX85 and 125 he always wore full yellow gear, since he moved to GPs, he started using diffrent collor gear, but yellow is still his, and his father's signature color.

Just a little backgroung so you guys know from where the whole yellow-red gear came from

That some good looking gear it sucks fox never make there best looking gear like roczen a1 kit or reeds 228 helment