It will be a lot of work to code something like that in MPL from scratch I suspect. Take a look at BioPython, which has some graphical tools.
If you just want to view a sequence and its translation, I would suggest using a proper browser like SnapGene, Artemis, Geneious, CLC, Jalview or any number of other alternatives.
What does that mean? How should your plot look like?
I want to plot the sequence in a straight line....different color for A T G and C
Still not clear to me. Do you have an example? Or can you draw something on paper?
https://ibb.co/nNcc58 I want something just like the circled area..
It's a shame it took us 11 hours to figure out what you need, while that information should have been part of your initial question.
See also How to add images to a Biostars post
sorry for that ...can you help me ?