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

What is data and data2? Both of Sander's suggestions should have worked fine.

Hi again Sander,

I am sorry to say that your statement plots only data2 (albeit in red), but not data.

Perhaps this problem is harder to resolve than we think.

Strange

Hi Sander,

Thanks very much for your recommendation to read the Documentation. That never occurred to me!

However, your suggestion does not seem to work. The statement

Show[ListPlot[data2], ListPlot[data], PlotRange -> All, PlotStyle -> {Red, Black}]

still results in both datasets being plotted in Black.

Thanks anyway.

Strange

Hi Sander,

I think you missed my point. I want to color one dataset red, while the other remains black.

And I still do not know how to accomplish this.

Strange