Yes. Breath is also such object of meditation. There are many different objects of visualisation for Shamatha practise. For instance, I have seen many Tibetan Buddhists (here, Karma Kagyu Karmapa) advising to choose object similar to practise of tonglen instead of focusing on breath (in mindfulness of breath).
The important part is that you have to abandon and let go of it it to experience nimitta.
From Ajahn Brahm's - "Stepping towards Enlightement":
As your unbroken mindfulness watches the breath calming down, joy
(step five) and happiness (step six) naturally arise like the golden
light of dawn on an eastern horizon.
The breath at these fifth and sixth steps appears
so tranquil and beautiful—more attractive than a garden in springtime
or a sunset in the summer—that you wonder if you will ever want to
look at anything else. As the breath becomes ever more beautiful, as
the joy and happiness grow in quiet strength, your breath may seem to
completely disappear. This seventh step does not happen when you want
it to but when there is enough calm.
Just as the Cheshire Cat [Alice in Wonderland] disappeared and left only its grin, so the
meditator’s body and breath disappear, leaving only the beautiful.
For Alice, it was the most curious thing she ever saw. For the meditator it is also strange, to clearly experience a free-floating beauty with
nothing to embody it, not even a breath.
Two common obstacles occur after this
seventh step: exhilaration and fear. In exhilaration, the mind becomes
excited: “Wow, this is it!” If the mind thinks like this, then the
jhana is unlikely to happen. This “wow!” response needs to be subdued
in the eighth step of anapanasati in favor of absolute passivity. You
can leave all the wows until after emerging from the jhana, where they
properly belong. The more likely obstacle, though, is fear.
Only after overcoming the eight phase, nimitta arises.