This is a shrub that was a sport of B. ‘Royal Red’. It bears panicles of fragrant red-purple flowers with yellow and green variegated leaves.
Any reversion i.e. green shoots with no variegation should be removed;
Possible better is B. davidii ‘Santana’.
This cultivar has been in cultivation since 1964 having originated as a sport of B. davidii ‘Royal Red’.