Color blobs mouse mode is choosing transparent colors

[goddard@…]

The following bug report has been submitted:
Platform:        macOS-26.5.2-arm64-arm-64bit-Mach-O
ChimeraX Version: 1.13.dev202607102107 (2026-07-10 21:07:32 UTC)
Description
Color blobs mouse mode colors the first blob an opaque color but subsequent blobs get a transparent color.  Why transparent?  Same behavior in ChimeraX 1.12.

Log:
UCSF ChimeraX version: 1.13.dev202607102107 (2026-07-10)  
© 2016-2026 Regents of the University of California. All rights reserved.  
How to cite UCSF ChimeraX  

> open 55878 format ccp4 fromDatabase emdb

Opened emdb 55878 as #1, grid size 440,440,440, pixel 0.65, shown at level
0.122, step 1, values float32, fit PDB 9tfv  

> volume #1 level 0.441

> ui tool show "Measure and Color Blobs"

> measure blob #!1.1 triangleNumber 4008 color #0000ccff outline true

Surface emdb 55878 #1.1 blob:  
volume = 17.426  
area = 37.085  
size = 5.2458 2.9716 2.2745  
  
/Users/goddard/ucsf/chimerax/ChimeraX.app/Contents/Library/Frameworks/Python.framework/Versions/3.14/lib/python3.14/site-
packages/chimerax/pick_blobs/pickblobs.py:268: RuntimeWarning: overflow
encountered in scalar add  
alpha = (vc[v0][3] + vc[v1][3] + vc[v2][3]) // 3  

> measure blob #!1.1 triangleNumber 20258 color #db566354 outline true

Surface emdb 55878 #1.1 blob:  
volume = 602.14  
area = 1025.3  
size = 34.929 20.172 10.864  
  

> measure blob #!1.1 triangleNumber 31281 color #ab967354 outline true

Surface emdb 55878 #1.1 blob:  
volume = 82.877  
area = 160.53  
size = 20.15 6.2784 4.4765  
  




OpenGL version: 4.1 Metal - 90.5
OpenGL renderer: Apple M2 Ultra
OpenGL vendor: Apple

Python: 3.14.6
Locale: C.UTF-8
Qt version: PyQt6 6.10.2, Qt 6.10.0
Qt runtime version: 6.10.2
Qt platform: cocoa
Hardware:

    Hardware Overview:

      Model Name: Mac Studio
      Model Identifier: Mac14,14
      Model Number: Z1800003VLL/A
      Chip: Apple M2 Ultra
      Total Number of Cores: 24 (16 Performance and 8 Efficiency)
      Memory: 64 GB
      System Firmware Version: 18000.121.3
      OS Loader Version: 18000.121.3

Software:

    System Software Overview:

      System Version: macOS 26.5.2 (25F84)
      Kernel Version: Darwin 25.5.0
      Time since boot: 14 days, 22 hours, 17 minutes

Graphics/Displays:

    Apple M2 Ultra:

      Chipset Model: Apple M2 Ultra
      Type: GPU
      Bus: Built-In
      Total Number of Cores: 60
      Vendor: Apple (0x106b)
      Metal Support: Metal 4
      Displays:
        PHL 278B1:
          Resolution: 3840 x 2160 (2160p/4K UHD 1 - Ultra High Definition)
          UI Looks like: 1920 x 1080 @ 60.00Hz
          Main Display: Yes
          Mirror: Off
          Online: Yes
          Rotation: Supported


Installed Packages:
    accessible-pygments: 0.0.5
    aiohappyeyeballs: 2.7.1
    aiohttp: 3.13.4
    aiosignal: 1.4.0
    alabaster: 1.0.0
    annotated-types: 0.7.0
    anyio: 4.14.1
    appdirs: 1.4.4
    appnope: 0.1.4
    asttokens: 3.0.1
    attrs: 26.1.0
    babel: 2.18.0
    beautifulsoup4: 4.13.5
    blockdiag: 3.0.0
    blosc2: 4.8.0
    build: 1.5.0
    certifi: 2026.6.17
    cftime: 1.6.5
    charset-normalizer: 3.4.9
    ChimeraX-AddCharge: 1.5.20
    ChimeraX-AddH: 2.3.1
    ChimeraX-AlignmentAlgorithms: 2.0.2
    ChimeraX-AlignmentHdrs: 3.6.2
    ChimeraX-AlignmentMatrices: 2.1
    ChimeraX-Alignments: 3.2.2
    ChimeraX-AlphaFold: 1.0.1
    ChimeraX-AltlocExplorer: 1.2
    ChimeraX-AmberInfo: 1.0
    ChimeraX-Animations: 1.0
    ChimeraX-Aniso: 1.3.2
    ChimeraX-Arrays: 1.1
    ChimeraX-Atomic: 1.70.2
    ChimeraX-AtomicLibrary: 14.4.2
    ChimeraX-AtomSearch: 2.0.1
    ChimeraX-AxesPlanes: 2.4
    ChimeraX-BasicActions: 1.1.3
    ChimeraX-BILD: 1.0
    ChimeraX-BlastProtein: 3.0.0
    ChimeraX-Boltz: 1.1
    ChimeraX-BondRot: 2.0.4
    ChimeraX-BugReporter: 1.0.2
    ChimeraX-BuildStructure: 2.13.1
    ChimeraX-Bumps: 1.0
    ChimeraX-BundleBuilder: 1.6.0
    ChimeraX-ButtonPanel: 1.0.1
    ChimeraX-CageBuilder: 1.0.1
    ChimeraX-CellPack: 1.0
    ChimeraX-Centroids: 1.4.1
    ChimeraX-ChangeChains: 1.1
    ChimeraX-CheckWaters: 1.5
    ChimeraX-ChemGroup: 2.0.2
    ChimeraX-Clashes: 2.4
    ChimeraX-Cluster: 1.0
    ChimeraX-ColorActions: 1.0.5
    ChimeraX-ColorGlobe: 1.0
    ChimeraX-ColorKey: 1.5.8
    ChimeraX-CommandLine: 1.3.1
    ChimeraX-ConnectStructure: 2.0.1
    ChimeraX-Contacts: 1.0.1
    ChimeraX-Core: 1.13.dev202607102107
    ChimeraX-CoreFormats: 1.2
    ChimeraX-coulombic: 1.4.6
    ChimeraX-Crosslinks: 1.0
    ChimeraX-Crystal: 1.0
    ChimeraX-CrystalContacts: 1.0.1
    ChimeraX-DAQplugin: 1.0.0
    ChimeraX-DataFormats: 1.2.4
    ChimeraX-DistMonitor: 1.4.2
    ChimeraX-DockPrep: 1.2.2
    ChimeraX-Dssp: 2.0
    ChimeraX-EMDB-SFF: 1.0
    ChimeraX-ESMFold: 1.0
    ChimeraX-FileHistory: 1.0.1
    ChimeraX-FunctionKey: 1.0.1
    ChimeraX-Geometry: 1.3
    ChimeraX-gltf: 1.0
    ChimeraX-Graphics: 1.4.1
    ChimeraX-Hbonds: 2.5.4
    ChimeraX-Help: 1.3
    ChimeraX-HKCage: 1.3
    ChimeraX-IHM: 1.1
    ChimeraX-ImageFormats: 1.2
    ChimeraX-IMOD: 1.0
    ChimeraX-IO: 1.0.4
    ChimeraX-ItemsInspection: 1.0.1
    ChimeraX-IUPAC: 1.0
    ChimeraX-KVFinder: 1.8.5
    ChimeraX-Label: 1.5
    ChimeraX-LightingGUI: 1.0
    ChimeraX-ListInfo: 1.3.1
    ChimeraX-Log: 1.2.2
    ChimeraX-LookingGlass: 1.1
    ChimeraX-Maestro: 1.9.3
    ChimeraX-Map: 1.3
    ChimeraX-MapData: 2.0
    ChimeraX-MapEraser: 1.0.1
    ChimeraX-MapFilter: 2.0.1
    ChimeraX-MapFit: 2.0
    ChimeraX-MapSeries: 2.1.1
    ChimeraX-Markers: 1.0.1
    ChimeraX-Mask: 1.0.2
    ChimeraX-MatchAlign: 1.2.1
    ChimeraX-MatchMaker: 2.4.1
    ChimeraX-MCopy: 1.0
    ChimeraX-MCPServer: 0.2.0
    ChimeraX-MDcrds: 2.19.2
    ChimeraX-Meeting: 1.0.1
    ChimeraX-Minimize: 1.4.2
    ChimeraX-MLP: 1.1.1
    ChimeraX-mmCIF: 2.17
    ChimeraX-MMTF: 2.2
    ChimeraX-ModelArchive: 1.0
    ChimeraX-Modeller: 1.5.24
    ChimeraX-ModelPanel: 1.6.1
    ChimeraX-ModelSeries: 1.0.1
    ChimeraX-Mol2: 2.0.3
    ChimeraX-Mole: 1.0
    ChimeraX-Morph: 1.0.2
    ChimeraX-MouseModes: 1.2
    ChimeraX-Movie: 1.0.1
    ChimeraX-MutationScores: 1.0
    ChimeraX-Neuron: 1.0
    ChimeraX-NMRSTAR: 1.0.2
    ChimeraX-Nucleotides: 2.0.3
    ChimeraX-OpenCommand: 1.16.2
    ChimeraX-OpenFold: 1.0
    ChimeraX-OrthoPick: 1.0.1
    ChimeraX-PDB: 2.7.13
    ChimeraX-PDBBio: 1.0.1
    ChimeraX-PDBLibrary: 1.0.5
    ChimeraX-PDBMatrices: 1.0
    ChimeraX-PickBlobs: 1.0.1
    ChimeraX-Positions: 1.0
    ChimeraX-PresetMgr: 1.1.4
    ChimeraX-ProfileGrids: 1.10.2
    ChimeraX-ProNA3D: 0.1
    ChimeraX-PubChem: 2.2
    ChimeraX-ReadPbonds: 1.0.1
    ChimeraX-Registration: 1.1.2
    ChimeraX-RemoteControl: 1.0
    ChimeraX-RenderByAttr: 1.8.3
    ChimeraX-RenumberResidues: 1.1
    ChimeraX-ResidueFit: 1.0.1
    ChimeraX-RestServer: 1.3.3
    ChimeraX-RNALayout: 1.0
    ChimeraX-RotamerLibMgr: 4.0
    ChimeraX-RotamerLibsDunbrack: 2.0
    ChimeraX-RotamerLibsDynameomics: 2.0
    ChimeraX-RotamerLibsRichardson: 2.0
    ChimeraX-SaveCommand: 1.5.2
    ChimeraX-Scenes: 0.3.1
    ChimeraX-SchemeMgr: 1.0
    ChimeraX-SDF: 2.0.3
    ChimeraX-Segger: 1.0
    ChimeraX-Segment: 1.0.1
    ChimeraX-Segmentations: 3.5.12
    ChimeraX-SelInspector: 1.0
    ChimeraX-SeqView: 2.19.1
    ChimeraX-Shape: 1.1
    ChimeraX-Shell: 1.0.1
    ChimeraX-Shortcuts: 1.2.1
    ChimeraX-ShowSequences: 1.0.3
    ChimeraX-SideView: 1.0.1
    ChimeraX-SimilarStructures: 1.0.1
    ChimeraX-Smiles: 2.1.2
    ChimeraX-SmoothLines: 1.0
    ChimeraX-SNFG: 1.0
    ChimeraX-SpaceNavigator: 1.0
    ChimeraX-StdCommands: 1.20
    ChimeraX-STL: 1.0.1
    ChimeraX-Storm: 1.0
    ChimeraX-StructMeasure: 1.2.1
    ChimeraX-Struts: 1.0.1
    ChimeraX-Surface: 1.0.1
    ChimeraX-SwapAA: 2.0.1
    ChimeraX-SwapRes: 2.5.3
    ChimeraX-TapeMeasure: 1.0
    ChimeraX-TaskManager: 1.0
    ChimeraX-Test: 1.0
    ChimeraX-Toolbar: 1.2.4
    ChimeraX-ToolshedUtils: 1.2.4
    ChimeraX-Topography: 1.0
    ChimeraX-ToQuest: 1.0
    ChimeraX-Tug: 1.0.1
    ChimeraX-UI: 1.53.1
    ChimeraX-Umap: 1.0
    ChimeraX-uniprot: 2.3.2
    ChimeraX-UnitCell: 1.0.1
    ChimeraX-ViewDock: 1.6.5
    ChimeraX-VIPERdb: 1.0
    ChimeraX-Vive: 1.1
    ChimeraX-VolumeMenu: 1.0.1
    ChimeraX-vrml: 1.0
    ChimeraX-VTK: 1.0
    ChimeraX-WavefrontOBJ: 1.0
    ChimeraX-WebCam: 1.0.2
    ChimeraX-WebServices: 1.1.5
    ChimeraX-Zone: 1.0.1
    click: 8.4.2
    colorama: 0.4.6
    comm: 0.2.3
    contourpy: 1.3.3
    coverage: 7.15.0
    cxservices: 1.2.3
    cycler: 0.12.1
    Cython: 3.2.8
    debugpy: 1.8.21
    decorator: 5.3.1
    docutils: 0.21.2
    executing: 2.2.1
    filelock: 3.19.1
    flatbuffers: 25.12.19
    fonttools: 4.63.0
    frozenlist: 1.8.0
    funcparserlib: 1.0.1
    glfw: 2.10.0
    grako: 3.16.5
    h11: 0.16.0
    h2: 4.3.0
    h5py: 3.16.0
    hpack: 4.2.0
    html2text: 2025.4.15
    httpcore: 1.0.9
    httpx: 0.28.1
    httpx-sse: 0.4.3
    hyperframe: 6.1.0
    idna: 3.18
    ihm: 2.2
    imagecodecs: 2026.6.26
    imagesize: 2.0.0
    iniconfig: 2.3.0
    ipykernel: 7.3.0
    ipython: 9.14.1
    ipython_pygments_lexers: 1.1.1
    jedi: 0.20.0
    Jinja2: 3.1.6
    joblib: 1.5.3
    jsonschema: 4.26.0
    jsonschema-specifications: 2025.9.1
    jupyter_client: 8.9.1
    jupyter_core: 5.9.1
    kiwisolver: 1.5.0
    line_profiler: 5.0.0
    llvmlite: 0.47.0
    lxml: 6.0.2
    lz4: 4.4.5
    Markdown: 3.8.2
    markdown-it-py: 4.2.0
    MarkupSafe: 3.0.3
    matplotlib: 3.10.7
    matplotlib-inline: 0.2.2
    mcp: 1.18.0
    mdurl: 0.1.2
    mlx: 0.31.2
    mlx-metal: 0.31.2
    mrcfile: 1.5.4
    msgpack: 1.1.1
    multidict: 6.7.1
    narwhals: 2.23.0
    ndindex: 1.10.1
    nest-asyncio2: 1.7.2
    netCDF4: 1.7.4
    networkx: 3.3
    numba: 0.65.1
    numexpr: 2.14.1
    numpy: 2.4.6
    onnxruntime: 1.26.0
    OpenMM: 8.4.0
    openvr: 1.26.701
    packaging: 25.0
    ParmEd: 4.2.2
    parso: 0.8.7
    pep517: 0.13.1
    pexpect: 4.9.0
    pickleshare: 0.7.5
    pillow: 11.3.0
    pip: 26.1.2
    pkginfo: 1.12.1.2
    platformdirs: 4.10.0
    plotly: 6.8.0
    pluggy: 1.6.0
    prompt_toolkit: 3.0.52
    propcache: 0.5.2
    protobuf: 7.34.1
    psutil: 7.0.0
    ptyprocess: 0.7.0
    pure_eval: 0.2.3
    py-cpuinfo: 9.0.0
    pybind11: 3.0.1
    pycollada: 0.8
    pydantic: 2.13.4
    pydantic-settings: 2.14.2
    pydantic_core: 2.46.4
    pydata-sphinx-theme: 0.20.0
    Pygments: 2.18.0
    pyKVFinder: 0.9.3
    pynmrstar: 3.5.1
    pynndescent: 0.6.0
    PyOpenGL: 3.1.10
    PyOpenGL-accelerate: 3.1.10
    pyopenxr: 1.1.4501
    pyparsing: 3.3.2
    pyproject_hooks: 1.2.0
    PyQt6: 6.10.2
    PyQt6-Qt6: 6.10.2
    PyQt6-WebEngine: 6.10.0
    PyQt6-WebEngine-Qt6: 6.10.2
    PyQt6_sip: 13.10.3
    pytest: 9.1.1
    pytest-cov: 7.1.0
    python-dateutil: 2.9.0.post0
    python-dotenv: 1.2.2
    python-multipart: 0.0.32
    pyzmq: 27.1.0
    qtconsole: 5.7.2
    QtPy: 2.4.3
    qtshim: 1.2.2
    RandomWords: 0.4.0
    referencing: 0.37.0
    requests: 2.32.5
    rich: 15.0.0
    roman-numerals: 4.1.0
    rpds-py: 2026.6.3
    scikit-learn: 1.9.0
    scipy: 1.17.1
    setuptools: 82.0.1
    sfftk-rw: 0.8.1
    six: 1.17.0
    snowballstemmer: 3.1.1
    sortedcontainers: 2.4.0
    soupsieve: 2.8.4
    Sphinx: 9.0.4
    sphinx-autodoc-typehints: 3.6.1
    sphinxcontrib-applehelp: 2.0.0
    sphinxcontrib-blockdiag: 3.0.0
    sphinxcontrib-devhelp: 2.0.0
    sphinxcontrib-htmlhelp: 2.1.0
    sphinxcontrib-jsmath: 1.0.1
    sphinxcontrib-qthelp: 2.0.0
    sphinxcontrib-serializinghtml: 2.0.0
    sse-starlette: 3.4.5
    stack-data: 0.6.3
    starlette: 1.3.1
    superqt: 0.7.6
    tables: 3.11.1
    threadpoolctl: 3.6.0
    tifffile: 2025.3.13
    tinyarray: 1.2.5
    tomlkit: 0.15.0
    tornado: 6.5.7
    tqdm: 4.68.3
    traitlets: 5.15.1
    typing-inspection: 0.4.2
    typing_extensions: 4.16.0
    umap-learn: 0.5.12
    urllib3: 2.7.0
    uv: 0.11.26
    uvicorn: 0.51.0
    wcwidth: 0.8.2
    webcolors: 24.11.1
    wheel: 0.47.0
    wheel-filename: 1.4.2
    yarl: 1.24.2

[Tom Goddard]

ChimeraX 1.11.1 does not create transparent blobs, but 1.12 and 1.13 daily builds do.

[Tom Goddard]

Fixed.

There was an overflow in the computation of the clicked triangle opacity summing three uint8 alpha values. I'm not sure why this was bug was in ChimeraX 1.12 that used numpy 1. At any rate I changed the code to cast the uint8 alpha values to int before adding.