If temps and noise are your primary considerations, why not discard the idea of RGB fans and pay only for those features that actually offer COOLING performance, instead of "Wow, pretty lights", while charging twice as much for half the performance.
Not sure where you are able to purchase from in your country or region, but there are very good non-RGB fans available for much less than 280 euros, and it's highly doubtful you need six of them anyhow. If you are using an air CPU cooler you should be able to do well with two front intake, a rear exhaust and a top-rear exhaust. Putting another top exhaust fan in the middle or top front locations on systems with air coolers is a patently bad idea anyhow as that tends to allow the middle and top front exhaust fans to "steal" the cool ambient outside air coming in from your intake fans before it ever has a chance to reach your CPU cooler.
If you are using an AIO cooler, then you really only need to buy two fans, or, use the two fans that come with the case. Or, use the two fans that come with the case anyhow, regardless and simply add a couple more.
Making everything match is great, and getting great fans is great, but sometimes you have to settle for what you can actually afford while STILL getting something worth buying, and not settling for half ass quality parts in order to do so.
Maybe think about getting a less expensive case so that you can afford the better fans you would prefer to get. As far as non-RGB fans go, it's pretty hard to beat Noctua, Thermalright (NOT to be confused with Thermaltake) or Be Quiet, and Arctic cooling has some very decent budget fans if you have to settle for a less expensive fan. Aerocool has some decent DC controlled 3 pin fans as well, with single color LED lighting, in their DS series.