I vaguely remember seeing it flower yellow earlier this year before it spread across the yard but I didn't pay it much mind at the time because I was preoccupied with life. At some point 3 years ago someone tried to cut it down and it threw out a bunch of branches. The branches reach upwards of 10 meters high and up to 3 meters out sprawling across the lawn during spring. The branches are thornless and maybe 10-12mm thick. Each leaf set reaches as long and wide as my hand with several small branches of narrow leaves. I don't think I've seen it drop leaves even through our harsh winter freezes at 16*f or even lower. It's rather resilient that's for sure.
But in short, I believe it flowers yellow