The aids you have are not inherently tinny sounding. However, I’d say the software can have a tendency to set the aids a little too harsh sometimes. Your hearing professional should be able to adjust for that pretty easily.
Assuming you have a high frequency loss, you are likely to notice the change in sound at that range the most because you are do used to not hearing those sounds in such a while.
With a bit of work the hearing professional should be able to soften the sound, either with more compression, less gain in the HF, or even by experimenting with Spectral IQ (some people prefer it off, some like it on).
Find out what your algorithm is too. Some like e-STAT, some do better with NAL-R, just as an example. This can affect the ‘color’ of the sound, but again all a guess without knowing the loss you have.