This issue has been closed as 'Won't Fix' due to an extended period of time without updates. If this issue is important to you please let us know by posting on the AnswerHub or UDN, and Epic will re-open the ticket for further review.
GPU particles will not take a changing input from Initial Color when using a Vector Parameter to control through a blueprint.
1. Open the attached project
2. PIE (GPU Particles is the "taller" system)
RESULTS:
The GPU Particles are not reacting to changes to Initial Color in the Blueprint.
EXPECTED:
GPU Particles adjusted like CPU counterparts.
Head over to the existing Questions & Answers thread and let us know what's up.