Minecraft – Is the alpha channel supported in Minecraft tellraw

So I'm trying to add transparency to Minecraft tellraw so text can be partly transparent, and I'm stuck. I've tried to add it via hex code, in the format #AARRGGBB and the alpha value is completely ignored. I know it is supported in someway since I can use translucent images in unicode, I just don't know how to add it without using unicode. Is there a way to add it in the color value? Does Minecraft have a different value for alpha values? Or is this not possible? A solution without using unicode is what I need.