If I have designated utensils for cold foods such as salad, or cold salami and cheese. What is the problem of using the same utensils for both milk and meat, since there is no bliya because both are cold.
Dr. Haym Soloveitchik notes this anomaly (that really there's no need to have separate dishware for cold foods) in the beginning of his famous essay, Rupture and Reconstruction (second paragraph): "The simple fact is that the traditional Jewish kitchen, transmitted from mother to daughter over generations, has been immeasurably and unrecognizably amplified beyond all halakhic requirements". However, I think there's good reason for this, as one's liable to make a mistake pretty easily, especially since today food is dishes are washed with hot water (as pointed out in the comments).
See Sefer Pischei Halacha Kitzur Hilchos Kashrus (excellent sefer for the basics of kashrus)perek 1:20 brings the Shulchan Aruch 89:4 that forbids cutting bread with a meat knife by a dairy seudah and the opposite and the Rishonim were machmir when it came to cutting cheese even when cold with a meat knife .The reason for all this is because sometimes the fattiness of the food is left on the knife(see the Tur). However ,if you don't have another knife then one can do neitzah bkarka 10 times(Aruch Hashulchan seif 16 and Chochmas Adam 40:14 hold a kinuach is good enough when it comes to bread[some hold steel wool is like neitzah].
The custom of klal Yisroel is to have two separate flatware for meat and dairy(Aruch Hashulchan 16) so one does not mix them up,and the siman is always on the dairy not meat (Rama)
The Rama discusses a similar case of using glass for both meat and dairy. Even though bliyot are not possible, as they do not go into the glass, nevertheless the minhag is to be machmir because it will be confusing.
Using the same utensils should be even more chamur than glass where there is no possibility of bliyot.