If I were writing for The Flash I'd have every Flash's costume be based in the Speed Force (made of Speed Force) as ginger Wally's was prior to the New 52 and is as of Rebirth.
I would also have Barry be the only speedster capable of generating the Speed Force by running (as he was [and still might be] as of Geoff John's The Flash: Rebirth); because of this Barry would - as long as he were alive - ALWAYS be the fastest speedster connected to the positive Speed Force.
The positive Speed Force - similar to a running race - would be denoted by 3 colors; gold (fastest), silver (next fastest), bronze (slowest of the Positive Speed Force users).
Speedsters would have the ability to accelerate their speeds and could "earn" the next level of speed...once this level was reached (for example when Barry died and Wallace took over as The Flash during Infinite Crisis) their Speed Force based costume would change the color of their logo and it's accents to match their 'new level of speed'.
Furthermore, a speedster's offspring would be born with the level of speed immediatley preceding that of the original speedster in their familial tree. For example, ginger Wally/Wallace's daughter would have 'bronze' speed because her father had 'silver' speed when she was conceived. However, Bart Allen, Barry's grandson has "silver" speed; this is because Barry's speed is/was "gold".
Along with denoting a speedster's emblem color, it would also denote the accent color of their costume (ear-wings, belt, arm-bolts, boots, etc.) as well as the color of their lighting.
Meaning the positive speed force is denoted by three colors: gold, silver, and bronze.
Speaking to the Quick-family; since their connection to the Speed Force is considered 'unnatural' they can ONLY tap into the mid-tier of speed (silver) and cannot get any faster or slower than that tier.
Similar to the Quick's John Fox (who also unnaturally tapped into the Speed Force) opted to use a logo similar to Barry's but - due to his inability to access the top tier of the Sped Force - has a silver color scheme.