I think that plant in your OP is a dieffenbachia. I've kept mine in a HOB nicely w/o problems. I've had a 6CFL fixture on all emersed growth.
Yellow leaves could also be a number of combining factors, such as low Mg, water temp, alkanity, etc. One or two yelllow leaves/stems is also normal for dieffenbachias, just pull them off
So believe me, you can still keep its roots submerged in your tank.
My 15 gal has anthurium, spider, iresine, jasminium, spath, lucky bamboo, and the diffenbachia in the angle of this picture unfortunately has only one leaf visible, but trust me there are 4-5 other large ones there with the white patches on them. The white patch Ive reads shows up when there's sufficient light and it's due to a "virus" activated in plant.