To change the color of blooms on a tropical hibiscus tree, you need to plant and care for the right kind of hibiscus, which is hibiscus mutabilis, also known as confederate rose. While specific bloom color is beyond your control, you can ensure you see each color during its blooming season with proper care. You need pruning shears, fertilizer and mulch.
Plant the tree in a suitable location
Despite its nickname of confederate rose, hibiscus mutabilis is a tropical hibiscus. Plant hibiscus mutabilis in well-draining soil in either full sunlight or partial shade. Protect it from cold winds and frost pockets. In autumn, apply 2 to 4 inches of mulch around the tree, but keep it away from the trunk.
Water and fertilize the plant
During spring through early autumn, water the plant generously at least once a week. Every year, feed it a slow-release fertilizer designed for flowering shrubs.
Prune the plant
As blossoms fade, remove them from the plant. In late winter or early spring, before the beginning of new growth, prune hibiscus mutabilis. Cut off dead, damaged or diseased branches, as well as branches that are crossing or crowding each other. Trim other stems to create the shape you want. Untrimmed, the tree grows up to 15 feet high and 10 feet wide. When it blooms from summer through autumn, its flowers are first white, then turn pale pink and finally deep pinkish-red over a three-day period. The flowers change color independently of each other, so you may have white, pink and red blossoms at the same time.