Best crack filler for exposed aggregate?

[stm317]

My front porch has a long, narrow crack that I'd like to fill and hopefully prevent further damage from freeze/thaw cycles. It's fine enough that it's easily missed if you're not looking for it, so grinding it out or filling with backer rod, etc isn't an option. I've got some Legacy Extreme Set left over from my shop that I might try, but wanted to ask here to see if anyone had better ideas. I'm looking for something that won't need to be ground down since that would wreck the aggregate surface, and it would be great to find something that would sort of match the color of the surface since it's already difficult to see, I'd rather not make the crack stand out any more than it already does. Surface texture isn't super critical. Anybody filled cracks in exposed aggregate before?

 

[Armorpoxy]

Hi,
Metzger and McGuire sells flexible polyurea caulks (you need a dual caulk Gun) in over 100 colors. Amazing product which out our Installation Division uses all the time. We don't carry it for resale, but available from many sources. Color chart below. Ideal product for where you want a floor done with expansion joints that won't crack if covered with epoxy but is the correct color to match your floor. Also they are good at sending free samples of the colors in your color range to see which matches best.

http://www.metzgermcguire.com/images/stories/colorfast/ColorFast Color Chart V1-15.pdf