I think the way to be cool, is to be authentically yourself. Authentically weird.
I'm considered "cool" not because I'm up with the trends of people my age, but because I follow my own path. I have my own fashion sense that's very "modern day sorceress/nature goddess". I've worked on my self for about 15 years, and now I feel very centered in who I am and what I like and what I want. I go to tech conferences dressed in flowing orange and teal gowns with butterfly headdresses. And I come away having made plenty of sales and being one of the most memorable people there. Just because I was myself (the person I am outside of work) at the conference as well.
It's never too late to be flamboyant. It's never too late to create the new wave. I follow an Instagram page called "Advancedstyle" which is about octogenarians who wear the most amazing colourful outfits, and live such vibrant lives. I'm friends with a couple in their 80s who started ecstatic dance 20 years ago and now are the beloved elders of the community who help set the tone for the whole group.
You can create your own paradigm. Then people will say "wow how cool" when they have the privilege to interact with it.