thanks for all the replies and nice comments. My own opinion about needing a female is similar to the answer posted. My blackbelt has been alone for years, until a year ago I added 2 plecos. Shortly thereafter never did find one of them or even a carcass. So only one remains, and is doing well.
The blackbelt doesn't want the pleco anywhere but one corner of the tank where it can hide behind some driftwood and be safe. Otherwise he chases it around the tank with some minor nudges and bites, although never really inflicting wounds. It's not that he wants to eat all other fish, I believe he's just been ready to breed since at least 3 years old, and may have been sexually able since much younger. It's his normal instinct to create a large territory and defend it from uninvited guests. I also see him get very showy and beligerent if I ever turn out the living room lights while the tank lights are still on. He sees his own reflection in the front glass and goes into dominate mode! I have questioned whether some of the behavior is showing off for possible females or just threatening a perceived male intruder.
My fish started to get colorful at around 1 year old, and has been looking very colorful and beautiful since, but his color has continuously shifted a bit. He also can brighted or fade his colors with moods, even going to a pale white, to a darkish grey all over. This is rare to go to these extremes, but it has happened.
Bruce is now roughly 4 years old, has grown quite a bit since these last pics and is quite a bit thicker and deeper bodied, maybe an inch longer too. Overall everyone comments that he looks huge compared to when these pics were taken. He's also forming a slight nuchal hump finally (lump on the head). He is looking great, and looks much more mature than when these pics were taken, even though it's only been 7 or 8 months.
Females look a bit different, and generally a bit duller, but still good color for large cichlids. Also their fins won't get the larger extensions possible with males. Another thing is that some people have blackbelts without the red in the throught area, which is one of my favorite parts. Their colors can vary a bit from fish to fish, so just take good care of his water, feed him quality and variety, and watch what unfolds.
The key to a good looking fish is all about keeping high quality water with good old fashioned water changes. I now change 50% every two weeks, but the nitrates stay below 20ppm. Since he's moved to this 150 gallon tank I built, I over-feed like a mad-man, but only once a day. He could easily put away 15 JumboMin Food Sticks, although I tipically only give 10. I'm using this one food to show the amount of food that he eats, not a complete diet. I won't list all the foods he eats unless someone is interested, but suffiice it to say that he has a variety of 6 different prepared foods, as well as fresh vegies (variety of these too). Any other questions?