Anael, it takes a very special person to coach and relate to special persons who walk a different life. Each unique individual has a special talent and relate in their own way. Only very special people have the vision to see each unique personality of the 'mentally challenged'...others will avoid the issue. (The latter is me, most of the time. I get too emotionally involved to be helpful.)
If you think of brightening up their life, keep the design simple. The PC blocks may be beyond what many of them 'see'. And , yes, some may appreciate a bright color instead of the 'brown', but laundry may be the problem for them... to house so many that basic needs that are met first...not quite like home laundry where we sort out colors, or wash and wear, etc.
Dd (out on her own) taught me to keep things simple, so she had a wardrobe filled with earthy colors to wear and wash together. Yes, her IQ is very high, but she keeps her style simple and basic. I admire her abilities and common sense in daily life.