Here is a partial list of images that are possible to override using the theme folder.
- Trayicon.ico 
- 2XClientLarge.png 
- 2XClientSmall.png 
- AmmyyAdminLarge.png 
- AmmyyAdminSmall.png 
- AnydeskLarge.png 
- AnydeskSmall.png 
- AnyplaceControlLarge.png 
- AnyplaceControlSmall.png 
- AwrcProLarge.png 
- AwrcProSmall.png 
- AxelViewerLarge.png 
- AxelViewerSmall.png 
- AzureStorageExplorerLarge.png 
- AzureStorageExplorerSmall.png 
- BarracudaNgFirewallLarge.png 
- BarracudaNgFirewallSmall.png 
- BitviseSshClientLarge.png 
- BitviseSshClientSmall.png 
- BomgarRepresentativeConsoleLarge.png 
- BomgarRepresentativeConsoleSmall.png 
- CiscoAsdmLarge.png 
- CiscoAsdmSmall.png 
- CitrixNetscalerLarge.png 
- CitrixNetscalerSmall.png 
- ContactCompanyLarge.png 
- ContactCompanySmall.png 
- ContactCustomerLarge.png 
- ContactCustomerSmall.png 
- ContactDefaultLarge.png 
- ContactDefaultSmall.png 
- ContactEmployeeLarge.png 
- ContactEmployeeSmall.png 
- ContactFamillyLarge.png 
- ContactFamillySmall.png 
- ContactSupplierLarge.png 
- ContactSupplierSmall.png 
- ContactSupportLarge.png 
- ContactSupportSmall.png 
- CredentialAppleKeychainLarge.png 
- CredentialAppleKeychainSmall.png 
- CredentialChromePasswordManagerLarge.png 
- CredentialChromePasswordManagerSmall.png 
- CredentialConnectionStringLarge.png 
- CredentialConnectionStringSmall.png 
- CredentialDefaultLarge.png 
- CredentialDefaultSmall.png 
- CredentialFirefoxPasswordManagerLarge.png 
- CredentialFirefoxPasswordManagerSmall.png 
- CredentialKeePassLarge.png 
- CredentialKeePassSmall.png 
- CredentialLastPassLarge.png 
- CredentialLastPassSmall.png 
- CredentialOnePasswordLarge.png 
- CredentialOnePasswordSmall.png 
- CredentialPMProLarge.png 
- CredentialPMProSmall.png 
- CredentialPasswordBoxLarge.png 
- CredentialPasswordBoxSmall.png 
- CredentialPasswordSafeLarge.png 
- CredentialPasswordSafeSmall.png 
- CredentialPasswordVaultManagerLarge.png 
- CredentialPasswordVaultManagerSmall.png 
- CredentialPasswordstateLarge.png 
- CredentialPasswordstateSmall.png 
- CredentialPleasantPasswordServerLarge.png 
- CredentialPleasantPasswordServerSmall.png 
- CredentialPrivateKeyLarge.png 
- CredentialPrivateKeySmall.png 
- CredentialSecretServerLarge.png 
- CredentialSecretServerSmall.png 
- CredentialWindowsVaultLarge.png 
- CredentialWindowsVaultsmall.png 
- DataEntryAlarmLarge.png 
- DataEntryAlarmSmall.png 
- DataEntryBankInfoLarge.png 
- DataEntryBankInfoSmall.png 
- DataEntryCredentialLarge.png 
- DataEntryCredentialSmall.png 
- DataEntryCreditCardLarge.png 
- DataEntryCreditCardSmall.png 
- DataEntryCustomLarge.png 
- DataEntryCustomSmall.png 
- DataEntryEmailAccountLarge.png 
- DataEntryEmailAccountSmall.png 
- DataEntryPassportLarge.png 
- DataEntryPassportSmall.png 
- DataEntrySafetyDepositLarge.png 
- DataEntrySafetyDepositSmall.png 
- DataEntrySecureNoteLarge.png 
- DataEntrySecureNoteSmall.png 
- DataEntrySerialLarge.png 
- DataEntrySerialSmall.png 
- DataEntryWalletLarge.png 
- DataEntryWalletSmall.png 
- DataEntryWebLarge.png 
- DataEntryWebSmall.png 
- Database.NetLarge.png 
- Database.NetSmall.png 
- DbVisualizerLarge.png 
- DbVisualizerSmall.png 
- DocumentCertificateLarge.png 
- DocumentCertificateSmall.png 
- DocumentDefaultLarge.png 
- DocumentDefaultSmall.png 
- DocumentExcelLarge.png 
- DocumentExcelSmall.png 
- DocumentImageLarge.png 
- DocumentImageSmall.png 
- DocumentOneNoteLarge.png 
- DocumentOneNoteSmall.png 
- DocumentPDFLarge.png 
- DocumentPDFSmall.png 
- DocumentPhoneBookLarge.png 
- DocumentPhoneBookSmall.png 
- DocumentPowerPointLarge.png 
- DocumentPowerPointSmall.png 
- DocumentTextLarge.png 
- DocumentTextSmall.png 
- DocumentVisioLarge.png 
- DocumentVisioSmall.png 
- DocumentWordLarge.png 
- DocumentWordSmall.png 
- EricomBlazeClientLarge.png 
- EricomBlazeClientSmall.png 
- FileExplorerLarge.png 
- FileExplorerSmall.png 
- FlashfxpLarge.png 
- FlashfxpSmall.png 
- GateprotectFirewallAdministrationClientLarge.png 
- GateprotectFirewallAdministrationClientSmall.png 
- GroupCompanyLarge.png 
- GroupCompanySmall.png 
- GroupCustomerLarge.png 
- GroupCustomerSmall.png 
- GroupDatabaseLarge.png 
- GroupDatabaseSmall.png 
- GroupDeviceLarge.png 
- GroupDeviceSmall.png 
- GroupDomainLarge.png 
- GroupDomainSmall.png 
- GroupFolderLarge.png 
- GroupFolderSmall.png 
- GroupIdentityLarge.png 
- GroupIdentitySmall.png 
- GroupPrinterLarge.png 
- GroupPrinterSmall.png 
- GroupRootLarge.png 
- GroupRootSmall.png 
- GroupServerLarge.png 
- GroupServerSmall.png 
- GroupSiteLarge.png 
- GroupSiteSmall.png 
- GroupSoftwareLarge.png 
- GroupSoftwareSmall.png 
- GroupWorkstationLarge.png 
- GroupWorkstationSmall.png 
- HeidisqlLarge.png 
- HeidisqlSmall.png 
- HpIntegratedLightsOutLarge.png 
- HpIntegratedLightsOutSmall.png 
- IbmPersonalCommunicationsLarge.png 
- IbmPersonalCommunicationsSmall.png 
- IslLightDeskLarge.png 
- IslLightDeskSmall.png 
- JavaWebStartLarge.png 
- JavaWebStartSmall.png 
- MacroScriptAppleScriptLarge.png 
- MacroScriptAppleScriptSmall.png 
- MacroScriptAutoHotKeyLarge.png 
- MacroScriptAutoHotKeySmall.png 
- MacroScriptAutoITLarge.png 
- MacroScriptAutoITSmall.png 
- MacroScriptCommandLineLarge.png 
- MacroScriptCommandLineSmall.png 
- MacroScriptDatabaseQueryLarge.png 
- MacroScriptDatabaseQuerySmall.png 
- MacroScriptJitBitLarge.png 
- MacroScriptJitBitSmall.png 
- MacroScriptMacroLarge.png 
- MacroScriptMacroSmall.png 
- MacroScriptPSExecLarge.png 
- MacroScriptPSExecSmall.png 
- MacroScriptPowerShellLarge.png 
- MacroScriptPowerShellLocalLarge.png 
- MacroScriptPowerShellLocalSmall.png 
- MacroScriptPowerShellSmall.png 
- MacroScriptTemplateLarge.png 
- MacroScriptTemplateSmall.png 
- MacroScriptVBScriptLarge.png 
- MacroScriptVBScriptSmall.png 
- MacroScriptWASPPowerShellLarge.png 
- MacroScriptWASPPowerShellSmall.png 
- MacroScriptWMILarge.png 
- MacroScriptWMISmall.png 
- MobaxtermLarge.png 
- MobaxtermSmall.png 
- NavicatPremiumLarge.png 
- NavicatPremiumSmall.png 
- NetopGuestLarge.png 
- NetopGuestSmall.png 
- NetsupportManagerLarge.png 
- NetsupportManagerSmall.png 
- NomachineLarge.png 
- NomachineSmall.png 
- NxClientLarge.png 
- NxClientSmall.png 
- OfficeWord,ExcelAndPowerPointLarge.png 
- OfficeWord,ExcelAndPowerPointSmall.png 
- PdfLarge.png 
- PdfSmall.png 
- PenguinetSshClientLarge.png 
- PenguinetSshClientSmall.png 
- PgadminIiiLarge.png 
- PgadminIiiSmall.png 
- PowertermProLarge.png 
- PowertermProSmall.png 
- ProxyNetworks-ProxyMasterLarge.png 
- ProxyNetworks-ProxyMasterSmall.png 
- RemoteUtilities-ViewerLarge.png 
- RemoteUtilities-ViewerSmall.png 
- Remoteassistant365Large.png 
- Remoteassistant365Small.png 
- RoyalTsLarge.png 
- RoyalTsSmall.png 
- RvtoolsLarge.png 
- RvtoolsSmall.png 
- SapGuiLarge.png 
- SapGuiSmall.png 
- SapNetweaverLarge.png 
- SapNetweaverSmall.png 
- Sccm2012RemoteControlLarge.png 
- Sccm2012RemoteControlSmall.png 
- SecurecrtLarge.png 
- SecurecrtSmall.png 
- SecurefxLarge.png 
- SecurefxSmall.png 
- SessionADConsoleLarge.png 
- SessionADConsoleSmall.png 
- SessionAddOnLarge.png 
- SessionAddOnSmall.png 
- SessionAppleRemoteDesktopLarge.png 
- SessionAppleRemoteDesktopSmall.png 
- SessionAwsLarge.png 
- SessionAwsSmall.png 
- SessionAzureLarge.png 
- SessionAzureSmall.png 
- SessionAzureTableStorageLarge.png 
- SessionAzureTableStorageSmall.png 
- SessionCitrixWebLarge.png 
- SessionCitrixWebSmall.png 
- SessionCommandLineLarge.png 
- SessionCommandLineSmall.png 
- SessionComputerLarge.png 
- SessionComputerSmall.png 
- SessionContactLarge.png 
- SessionContactSmall.png 
- SessionCredentialLarge.png 
- SessionCredentialSmall.png 
- SessionDamewareLarge.png 
- SessionDamewareSmall.png 
- SessionDataEntryLarge.png 
- SessionDataEntrySmall.png 
- SessionDataReportLarge.png 
- SessionDataReportSmall.png 
- SessionDatabaseLarge.png 
- SessionDatabaseSmall.png 
- SessionDeskRollLarge.png 
- SessionDeskRollSmall.png 
- SessionDocumentLarge.png 
- SessionDocumentSmall.png 
- SessionDropBoxLarge.png 
- SessionDropBoxSmall.png 
- SessionFtpLarge.png 
- SessionFtpSmall.png 
- SessionGatewayLarge.png 
- SessionGatewaySmall.png 
- SessionGroupLarge.png 
- SessionGroupSmall.png 
- SessionHostLarge.png 
- SessionHostSmall.png 
- SessionHpRgsLarge.png 
- SessionHpRgsSmall.png 
- SessionHyperVLarge.png 
- SessionHyperVSmall.png 
- SessionICALarge.png 
- SessionICASmall.png 
- SessionInventoryReportLarge.png 
- SessionInventoryReportSmall.png 
- SessionItermLarge.png 
- SessionItermSmall.png 
- SessionLogMeInLarge.png 
- SessionLogMeInSmall.png 
- SessionPCAnywhereLarge.png 
- SessionPCAnywhereSmall.png 
- SessionPlayListLarge.png 
- SessionPlayListSmall.png 
- SessionPowerShellLarge.png 
- SessionPowerShellSmall.png 
- SessionPuttyLarge.png 
- SessionPuttySmall.png 
- SessionRDPConfiguredLarge.png 
- SessionRDPConfiguredSmall.png 
- SessionRadminLarge.png 
- SessionRadminSmall.png 
- SessionRemoteAssistanceLarge.png 
- SessionRemoteAssistanceSmall.png 
- SessionS3Large.png 
- SessionS3Small.png 
- SessionSNMPReportLarge.png 
- SessionSNMPReportSmall.png 
- SessionScreenConnectLarge.png 
- SessionScreenConnectSmall.png 
- SessionSessionToolLarge.png 
- SessionSessionToolSmall.png 
- SessionSkyDriveLarge.png 
- SessionSkyDriveSmall.png 
- SessionSpiceworksLarge.png 
- SessionSpiceworksSmall.png 
- SessionSyncLarge.png 
- SessionSyncSmall.png 
- SessionTeamViewerLarge.png 
- SessionTeamViewerSmall.png 
- SessionTerminalConsoleLarge.png 
- SessionTerminalConsoleSmall.png 
- SessionVMRCLarge.png 
- SessionVMRCSmall.png 
- SessionVMWareConsoleLarge.png 
- SessionVMWareConsoleSmall.png 
- SessionVMWareLarge.png 
- SessionVMWareSmall.png 
- SessionVNCLarge.png 
- SessionVNCSmall.png 
- SessionVPNLarge.png 
- SessionVPNSmall.png 
- SessionVirtualBoxLarge.png 
- SessionVirtualBoxSmall.png 
- SessionVirtualPCLarge.png 
- SessionVirtualPCSmall.png 
- SessionWebBrowserLarge.png 
- SessionWebBrowserSmall.png 
- SessionWindowsVirtualPCLarge.png 
- SessionWindowsVirtualPCSmall.png 
- SessionXWindowLarge.png 
- SessionXWindowSmall.png 
- SessionXenServerLarge.png 
- SessionXenServerSmall.png 
- SmartftpLarge.png 
- SmartftpSmall.png 
- SqlServerManagementStudioLarge.png 
- SqlServerManagementStudioSmall.png 
- StatusAddOnMissingLarge.png 
- StatusAddOnMissingSmall.png 
- StatusConnectedLarge.png 
- StatusConnectedSmall.png 
- SupermicroIpmiUtilitiesLarge.png 
- SupermicroIpmiUtilitiesSmall.png 
- SyncActiveDirectoryLarge.png 
- SyncActiveDirectorySmall.png 
- SyncCSVLarge.png 
- SyncCSVSmall.png 
- TeraTermProLarge.png 
- TeraTermProSmall.png 
- TextLarge.png 
- TextSmall.png 
- ToadLarge.png 
- ToadSmall.png 
- VisioLarge.png 
- VisioSmall.png 
- VmwareHorizonViewClientLarge.png 
- VmwareHorizonViewClientSmall.png 
- VmwareRemoteConsoleLarge.png 
- VmwareRemoteConsoleSmall.png 
- WinboxLarge.png 
- WinboxSmall.png 
- XmailManagerLarge.png 
- XmailManagerSmall.png 
- XmanagerLarge.png 
- XmanagerSmall.png 
- XshellLarge.png 
- XshellSmall.png 
- ZocLarge.png 
- ZocSmall.png 
It is possible to personalize the splashscreen by adding a splashscreen.png file in Images\Themes The recommended size is 520 by 320 but the window will automatically adapt to the image.