I think the black would be best because if you ever get sick of your colour than your boots won't look funny with whatever new stuff you buy. I wish I had gotten black instead of my mauvey-purpley colour lol. They look like very nice boots too!
They look good. As long as you don't plan on using them for intense work because the velcro may fray and deteriorate. I would go for black because it is more versatile. If it is support for a bowed tendon during recreational jumping you want, polos are a cheap option to consider. While maybe not as strong or supportive they do support and prevent further injuring the leg and are much cheaper (and you can get any color you want)