I am trying to open a gpx file in Qgis, with works just fine. the problem however is that it contains multply tracks. When I walk my tracks in the app "Galileo", I give the tracks specific colors. Can I somehow open it up Qgis with the color information? Right now Qgis just give the tracks random colors,
It depends on which device/app generated the GPX file. A GPX file is a type of XML file. The X in XML is for "eXtensible", and a GPX file is also extensible. The only data fields that are required by the GPX standard are the X and Y coordinates for the point, but the GPX schema includes available fields for timestamp, track name, and a bunch of other attributes.
Color is not part of the GPX schema, but because it's an XML file format, you can add other data fields, and it looks like Garmin has done that with their GPS Extensions: One of those available attributes is a color for displaying the point/line feature. So if your GPX files were captured with a Garmin, they may include color information, and that may be what your app is reading to display the colors. If that data exists in your file, you can have QGIS (or any other GIS) use that field to assign colors to your tracks, though it won't do it automatically.
GPX/XML files are text files, so to check if yours contain color data, you can open it in Notepad++ or some other editor and search for the word "color". If your file is using the Garmin extensions, you'll find it.