As you're going minimal planting, I'd add more height & interest with big stones (rather than small pebbles) or big driftwoodhttps://www.completeaquatics.co.uk/...-for-aquariums/marina-beach-pebbl-2kg-12-18mm
I have 2 bags of those on order already, the idea is that they are similar in color to the gravel so will hopefully add more detail with larger grains.