P{UAS-mBitbow.2.0} 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 (placed at a distance to the 'mBitbow' cassette within the transgene). 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. P{UAS-mBitbow.2.0} 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), and can thus produce 31 different fluorescent color combinations. The self-regulating FLP module in P{UAS-mBitbow.2.0} consists of the nSyb promoter driving expression of FLP, with the FLP coding sequence flanked by a pair of FRT13 sites (in the same orientation). This design results in a strong burst of neuron-specific expression of FLP, 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 FRT13 sites; the use of the less efficient FRT13 sites is designed to allow sufficient recombination in the 'mBitbow' cassette prior to self-excision of the FLP source.