PBac{UAS-mBitbow2.2} is a multicolor cell labeling tool designed to be used for neuron morphology and network analysis. It contains both a 'mBitbow' cassette and a self-regulating FLP module. The 'mBitbow' cassette consists of multiple fluorescent protein (FP) coding units, each of which is tagged at the N-terminal end with Tag:Myr(Src64B) to ensure localization to the cell membrane, with each of these fusion proteins flanked by a pair of FLP recombinase target sites that will recombine with each other but which are incompatible with all the other pairs of FLP recombinase target sites in the transgene. UAS regulatory sequences are positioned upstream of each FP coding unit, although in the absence of FLP recombinase, no FP expression is expected as each coding sequence is initially in reverse orientation. In the presence of FLP recombinase each FP coding unit can stochastically and independently flip orientation into a forward or reverse expression state, resulting in a number of possible color combinations. PBac{UAS-mBitbow2.2} contains five fluorescent protein coding units, encoding Tag:Myr(Src64B)-tagged mAmetrine, mTFP1, mNeonGreen, mKO2 and tdKatushka2 (flanked by a pair of FRT3, FRT14, FRT545, FRT13 and FRT4 sites respectively). The self-regulating FLP module in PBac{UAS-mBitbow2.2} consists of the nSyb promoter upstream of an excisable FRT15 cassette that itself contains 1. a pair of inverted KDRT sites flanking coding sequence for the N-terminal part of FLP ('FlpN'), with the FlpN coding sequence in reverse orientation, and 2. coding sequence for the C-terminal part of FLP (in sense orientation), followed by a polyadenylation signal. In the absence of KDR recombinase, no functional FLP recombinase is produced. In the presence of KDR, inversion of the 'FlpN' coding sequence (via the KDRT sites) reconstitutes a functional FLP recombinase, which can act on the 'mBitbow' cassette to generate color combinations for neuron morphology and network analysis, before self-excision of the FLP coding sequence by recombination between the flanking FRT15 sites; the use of the less efficient FRT15 sites is designed to allow sufficient recombination in the 'mBitbow' cassette prior to self-excision of the FLP source.