If they are heterozygous and pink is dominant over yellow, this means that both Patrick and Patti have the following genotype: Pp.
Therefore, we should create a Punnet square crossing Pp x Pp, as follows:
There are one PP (homozygous dominant), two Pp (heterozygous) and one pp (homozygous recessive) in the diagram. So PP represents 1/4 (or 25%), Pp represents 2/4 (or 50%) and pp represents 1/4 (or 25%).
It is important to note that PP and Pp both will lead to a pink color, and only pp will lead to a yellow color.
Therefore:
The chances of a child with a pink body are three out of four, or 75%
The chances of a child with a yellow body are one out of four, or 25%