Newbie with Flashforge Issues: Help please

Hi All, brand new to 3d printing and the forum. We purchased a 3d printer for my son for Xmas. He has been doing pretty well with it. However, is has been trying to print phone stands using various color Flashforge PLA filament. The black is completely fine, however, so far grey and orange are not cooperating. It is delaminating towards the top, thinner portion of the stand. We have tried to change the settings. The last one we tried using Flashprint was high resolution; layer height .12, 20% infill, print speed of 25 and travel speed of 55, temp max at 240 and 100. What are we doing wrong. Don't understand why the black would work with a 5 hour print and the orange/grey fail on a 5 hour print, 12 hour and 15.5 hour. Can someone educate us a little.

Sorry...it is a Flashforge Adventurer 3 lite