The Yeezy Boost 380 “Alien Blue” is a May 2021 colorway of Kanye West’s evolutionary mid-top signature shoe. The “Alien Blue” marks the second time that West and yeezy have used the “Alien” moniker on the Yeezy Boost 380, with the first instance coming back in November 2019 on the model’s debut colorway. Like the original “Alien,” the “Alien Blue” features a sock-like cream-colored Primeknit base with a contrasting grey digi-camo-like pattern woven into the fabric. Perforations on both sides of the shoe allows for constant airflow. Despite its sock-like construction, a traditional lacing system is incorporated within the flexible knit upper for a lockdown fit. Underfoot, an icy Alien Blue colored Boost midsole completes the look. Release date: May 31, 2021.
| US size | UK sizes | Insole Length(MM) |
| 3.5 | 3 | 215 |
| 4 | 3.5 | 220 |
| 4.5 | 4 | 225 |
| 5 | 4.5 | 230 |
| 5.5 | 5 | 235 |
| 6 | 5.5 | 235 |
| 6.5 | 6 | 240 |
| 7 | 6.5 | 245 |
| 7.5 | 7 | 250 |
| 8 | 7.5 | 255 |
| 8.5 | 8 | 260 |
| 9 | 8.5 | 265 |
| 9.5 | 9 | 265 |
| 10 | 9.5 | 270 |
| 10.5 | 10 | 275 |
| 11 | 10.5 | 280 |
| 11.5 | 11 | 285 |
| 12 | 11.5 | 290 |
| 12.5 | 12 | 290 |
| 13 | 12.5 | 295 |
| 13.5 | 13 | 300 |
| 14 | 13.5 | 305 |
| 14.5 | 14 | 310 |
| 15 | 14.5 | 315 |
| 15.5 | 15 | 320 |
| 17 | 16 | 325 |
