Hi Eyecatcher,
The halo is a darker center in roses that Mr. Moore marketed, using the name “halo” with that group of roses. As Kim mentions, Mr. Moore liked the Hulthemia blotch and decided to try to get a blotch (halo) by breeding roses with darker centers, apart from his work with Hulthemias, through selective breeding. The halo though is different from the Hulthemia blotch. His ‘Halo Sunshine’ was an amazing accomplishment - without any Hulthemia genes!