Clear for redgum recommendation?

I've got this small slab that I was asked to refinish. It was weathered, all grey and I set about sanding it back and it came out really well. I wet it down and man that made the grain pop. Then, once dry, I used Cabots exterior marine polyurethane clear and the timber was so dark that even in the sun it was too hard to see the black contrast of the number. I left it for a while but it never lightened up so I brushed a heap of turps on to remove as much as I could



I've sanded it back again to grain that's not as light as it was before and now I'm ready to coat again. Any recommendations as to what clear will work without darkening the grain too much? I've used that cabots stuff on tas oak, merbau and meranti before without issue, but no go for this particular bit of redgum.



This is what it looked like after final sanding





First bit of clear going on looked promising but it went darker





I don't have a pic of the front that shows how dark it got but this is the rear after turps was used to wash the clear away.