The airways depicted in white on the presentation (map) in your question are "VOR" Airways. Note they are preceded with a "V." (e.g. V378-499) They are routes between VOR ground stations. Depending on the type of map you are looking at the VOR Airways could be depicted in black (but will be preceded with a "V").
The blue airways depicted are low altitude RNAV (Area Navigation) routes. Note they are preceded with a "T" (e.g.T358). RNAV routes are not dependent upon ground stations.