May be you can buy them close to the color you need like these silver ones (you are going to have to high light the whole link and right click, then open in new tab to see, don't know why)
https://www.ebay.com/itm/80-EcoFins-Kit-Silver-Stick-on-Vortex-Generator-Semi-Truck-Trailer-Fuel-Economy/192464855314?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D57159%26meid%3Dd8d7f6d96d964ff99cb4767b4d3a5be3%26pid%3D100005%26rk%3D1%26rkt%3D4%26sd%3D192464894687%26itm%3D192464855314&_trksid=p2047675.c100005.m1851
when posting an e-bag link, you only need the info BEFORE the "?". in other words, just highlite before the ?, then copy-n-paste. that will take you right to the bag item.
hope this helps.
