Which version are you using? I can't remember the default color to be black! Should be blue-ish...
data = {{5.44, 1.}, {13.44, 1.31351}, {21.44, 1.74846}, {29.44, 1.83433}, {37.44, 2.06847}, {53.44, 2.36553}, {77.44, 2.53351}}
d = 0.68
p = 8
y110 = 2
y210 = 3
data2 = {{d*p, y110}, {(1 + d)*p, y210}}
ListPlot[{data, data2}, PlotStyle -> {Red, Black}]
notice that I omitted the extra List[...] command
