Dock icons colors are messed up
I'd be tempted to go for the 'fix it even if it's not broken' approach...


Fix permissions, check &amp; if necessary repair disk, using Disk Utility
Reset Home folder permissions &amp; ACLs using OnyX  - Maintenance tab/permissions, tick the box at the top then Execute.
Update to 10.10.5 using the 10.10.5 combo update, not the delta from App Store