regarding residential exterior painting- it seems some caulks will mold/mildew/algae quicker than others and look bad. Examples being caulked siding butt joints, caulked soffit/fascia joints. You paint and a year or so later the caulk joint’s specifically are darkening with organic growth. My question is are some caulks prone to that and others not? It’s been my thought that using an elastomeric sealant is best. If there are any paint pros, feel free to chime in.