Hi Mike, hi folks.
1 - RESIZING
After bringing a ship in your model, make sure it is in a group and resize it. If not in a group, group it first.
To resize, go inside the group with a double click on the group and use the Tape Measure Tool to measure a line of known length. Observe the length shown in the VCB. If not correct, type over the required value and then validate with the RETURN or the ENTER key. There is no need to click in the VCB since it is active as soon as you start using any tool.
SU will ask if you want to resize the active Group/Component. Click yes and then exit the group.
Repeat for any additional group (imported ship in your case).
If you dont use groups, SU will resize the whole model which may be OK for the first ship but will probably be not very good for the next one.
Of course, all this assume that your ship is actual 3D geometry and not just a picture. However, imported pictures can also be resized using the same measuring tool. And, since they normally import as groups, it saves a step.
2 - COLORING
See attached SU file for ideas. Note that you can modify existing colors by editing them.
All this and more is in the help.
Hull painting.skp