It's not the number of layers so much as the relative thickness. If you use thick 1095 and thin 15N20 you'll get a balanced dark-light look if you have a reasonable number of layers for the pattern at hand. If your layers are the same thickness, the bright will overpower the dark and it'll be a mostly shiny blade. Back in the 1980s when Damascus was becoming common, people used 1/4" thick 1095 and pure nickel foil, around 0.007" thick. That thin layer of bright made for a blade that was mostly dark. In the 1990s people discovered AISI A203E nickel steel. It was used for pressure vessels and came in 1/16 to 1/4" thickness. Mixing that with equal parts 1095 at 1/4" thickness made for a mostly bright blade. In the late 90s into the early 2000s we played with L6 for the nickel layer, since it was high carbon as well. But it doesn't play well with 1095, making for a difficult heat treat. Then in the 2000s we discovered 15N20, which comes in fairly thin stock and acts just like 1095 in heat treatment. Then 1084 made a re-appearance, and since it etches darker than 1095 due to the increased manganese, it became the alloy of choice for the dark layers. It comes in 1/4" thickness, and 15N20 comes in 0.065" and thinner. If you stack that up and make a billet, it comes out just about perfect.
The pattern you want has a great effect on how many layers you need. A twist doesn't really care how thick each layer is, and can be nice with as few as five layers or as many as a few hundred. Random doesn't do well until you get past 60 or so layers, up to around 300. Ladders and raindrop look best to most people between 150 and 350 layers.
The number of layers has a far more pronounced effect at low layer counts. With a billet of 1084/15N20 seven layers thick forged down to blade size without any folding or surface manipulation will give a very high contrast blade of broad bright stripes and dark zones. Take that up to 300 layers and it becomes almost uniform, with a much more subtle pattern. This can be jazzed up by doing a high-contrast etch. This is doing a deep etch to get topography
followed by darkening the dark layers while polishing the bright. This can be done by cold bluing, hot bluing (although that can screw up your tempering), or the latest version, the concentrated instant coffee etch. These darken the 1095 or 1084 while not bothering the 15N20 much. Then you polish the blade with a single thickness of the finest grit sandpaper you used prior to etching glued to a hard backer. This polishes only the high spots (the bright 15N20) but can't get into the valleys (the 1095 or 1084).
If you don't have a press or power hammer, twist patterns are your friend. They can look great with the least amount of heavy forging.