The more I think about it, the more I think you probably didn't screw anything up in the first place.
One of the first cutting boards I 'made' was just a chunk of 8/4 maple 12"x24". I loved it, but it warped so badly, it really just didn't set on the counter right. But there was something neat about a big thick chunk-o-wood on the counter.
The point is, the more scrubbed it and oiled it and used it, the better it looked. Well, except for the time I picked up a rocket hot lodge cast iron pan with my bare hand and had to set it down really quick and set it on the board. Got a really nice woodburned Lodge Cast Iron logo on the cutting board... Only a slight burn on my hand
Since then, I've made a number of edge and end grain boards and both seem to get better looking over time with the application of the oil and wax. At first, they always seemed to be dry, and would look funny. But the more oil and wax, the better they would look. I don't think it's necessarily something that can be reproduced at will. I think it takes time. Time to cut, and clean, and scrub, and oil...
So what I'm saying is that you've made a couple of really nice cutting boards, and I'll bet they just get better looking over time...