genes comes in pairs of two, each parent gives one gene from each pair of genes to the offspring. the normal parent can only give normal genes (ppss), no morph genes. the bumblebee (PpSs) can give pastel and spider, pastel, spider, or normal. The capital letters represent morph genes. lower case are just normal genes. you need two paired genes to make a baby.
PpSs is a big P and a big S so it is a pastel spider aka bumblebee
Ppss is just a big P so its pastel
ppSs is just a big S so its a spider
ppss has no big letters, so it's a normal.