  Gaia DR3 provided a first release of RP spectra and astrophysical parameters
for ultracool dwarfs. We used these Gaia RP spectra and astrophysical
parameters to select the most outlying ultracool dwarfs. These objects have
spectral types of M7 or later and might be young brown dwarfs or low
metallicity objects. This work aimed to find ultracool dwarfs which have Gaia
RP spectra significantly different to the typical population. However, the
intrinsic faintness of these ultracool dwarfs in Gaia means that their spectra
were typically rather low signal-to-noise in Gaia DR3. This study is intended
as a proof-of-concept for future iterations of the Gaia data releases. Based on
well studied subdwarfs and young objects, we created a spectral type-specific
color ratio, defined using Gaia RP spectra; this ratio is then used to
determine which objects are outliers. We then used the objects kinematics and
photometry external to Gaia to cut down the list of outliers into a list of
'prime candidates'. We produce a list of 58 Gaia RP spectra outliers, seven of
which we deem as prime candidates. Of these, six are likely subdwarfs and one
is a known young stellar object. Four of six subdwarf candidates were known as
subdwarfs already. The two other subdwarf candidates: 2MASS J03405673+2633447
(sdM8.5) and 2MASS J01204397+6623543 (sdM9), are new classifications.
