[BUG] Nested color tags not working if adjoint

[tkmikan]

Describe the bug
For nested bbcode tags, if two open tags of colors are adjoint, the latter one does not work.

To Reproduce

from rich.console import Console
console = Console()
print(list(console.render('[red][blue]this should be blue[/blue]red here[/red]')))

Expection: [Segment('this should be blue', Style.parse("blue")), Segment('red here', Style.parse("red")), Segment('\n', None)]
Actual: [Segment('this should be blue', Style.parse("red")), Segment('red here', Style.parse("red")), Segment('\n', None)]

Things work if a space is inserted between the open tags, or if either tag is not a color tag,

Platform
Platform: Linux and Mac
I belive it is not a platform specific issue.