Answer: The Knock Out family of roses was started by rose breeder Bill Radler when he crossed seedlings of 'Carefree Beauty' with 'Razzle Dazzle' to create the original Knock Out? rose. The family now includes varieties that range from blush to vibrant red, and even yellow. Some Knock Out roses are grafted and others are grown on their own root stock. I think yours are the grafted kinds and the vigorous root stocks are overtaking the grafted tops of your plants. The pale pink or mostly white flowers are evidence that the root stock is outgrowing the grafted dark red rose. The soil pH or nutritional level has nothing to do with the rose color so there's not much you can do to restore your roses to their original color other than to trace each stem down to the main stem and cut away those with the odd color flowers to give the red flowering stems more room to grow. Eventually you can get rid of the paler colors with selective pruning.
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