# Yellow O > Yellow O is a B2B outbound sales consultancy founded by Mark Colgan, based between London and Lisbon. It helps B2B SaaS companies (Seed to Series D) build outbound systems that generate pipeline through diagnostic audits, custom playbook design, AI workflow implementation, and SDR training. Mark has worked with 250+ companies including HiBob, Moss, Parallax, and Kinsta. Yellow O sits between two common models in the market: agencies that run outbound for you (creating dependency) and GTM engineers that build tools without sales strategy. Yellow O combines outbound strategy expertise with hands-on AI tool-building, then hands the system over so the client's team runs it independently. The core philosophy is: automate the process, master the conversation. Mark Colgan has 15+ years in B2B sales and marketing. He coaches at Clay Bootcamp, previously led the training for outbound prospecting at Sales Impact Academy, and has reviewed 100+ outbound sales tools at OutboundSalesTools.com. He publishes the Just Sales Stuff newsletter (3,000+ subscribers) and regularly publishes strategy videos on his YouTube channel (1,400+ subscribers). ## Services - [Outbound Diagnostics](https://yellowo.co.uk/audit-and-recommendations.html): Deep diagnostic covering ICP accuracy, messaging effectiveness, tech stack utilisation, rep productivity, signal usage, and AI readiness. Compares ICP against actual closed-won deals. Written report with prioritised action plan and video walkthrough. Three calls: onboarding, presentation, and 30-day follow-up. 2-3 weeks. - [Playbook Design and Build](https://yellowo.co.uk/playbook-sprint.html): 14-section complete outbound operating system covering ICP segmentation, persona mapping, messaging frameworks, talk tracks, multi-channel sequences, signal-based and volume-based plays, and sending governance. Includes AI workflow builds for enrichment waterfalls, signal detection, account research automation, and message drafting. Built inside the client's existing tools. The playbook also works as a context layer for AI tools. 4-6 weeks. - [Enablement and Advisory](https://yellowo.co.uk/training-and-workshops.html): Diagnostic-led workshops and one-on-one coaching covering cold calling, messaging, objection handling (Acknowledge-Neutralise-Ask framework), AI-assisted research, and tool adoption. Tailored to the client's playbook and ICP, not generic methodology. Coaching notes provided for team leads to reinforce behaviours. Optional monthly retainer for ongoing support. 4-6 weeks. - [Outbound Upgrade](https://marketing.yellowo.co.uk/upgrade): Free personalised video review of one live outbound sequence with actionable feedback. Zero commitment. - [Interactive Outbound Sales Playbook](https://yellowo.co.uk/playbook.html): A live example of the playbook Yellow O builds for clients, delivered as a searchable, askable tool rather than a static document. ## Ideal Clients - **Early-stage B2B SaaS (Seed to Series B):** Typically founder-led sales organisations with the first few SDRs or BDRs in place. The founder or CEO is still personally involved in sales or has just started building the team. They have raised funding and need pipeline to come from somewhere other than their network. They may be hiring their first SDR or have just hired one and realised they don't have a playbook to follow. They have probably bought a tool or two but aren't getting value from them yet. - **Established B2B SaaS (Series B to D):** More mature organisations with several BDRs, often split across different markets such as SMB, mid-market, and enterprise. The VP of Sales, CRO, or SDR Leader owns pipeline targets. Reps are in seat and outbound is running, but results aren't proportional to activity. Messaging is inconsistent across the team, new hires take too long to ramp, tools aren't connected properly, and reps are doing too much manually. ## Frameworks and Resources - [The Effective Seller Manifesto](https://yellowo.co.uk/the-effective-seller-manifesto.html): Mark's philosophy on balancing AI automation with human selling skills. The Effective Seller Framework divides sales activities into Automate, Augment, and Human Only. - [The Effective Seller Diagnostic](https://yellowo.co.uk/the-effective-seller-diagnostic.html): Interactive self-assessment scoring tool for B2B sales teams across foundations, automation and AI, and human skills. - [The Outbound Sales Audit](https://yellowo.co.uk/The-Outbound-Sales-Audit.html): 10-point diagnostic framework covering ICP, personas, account tiering, signals, messaging, channel strategy, tech stack, rep productivity, measurement, and coaching. - [60+ B2B Sales Signals](https://yellowo.co.uk/trigger-based-prospecting-how-to-use-intent-data-signals/): Comprehensive guide to signal-based prospecting with first-party, second-party, and third-party signal taxonomy. - [30+ Outbound Plays](https://yellowo.co.uk/outbound-plays-guide-how-to-choose-score-and-run-30-plays/): Full walkthrough of outbound plays including signal-based prospecting, multi-channel sequences, and cold calling frameworks. - [11 Cold Email Frameworks](https://yellowo.co.uk/11-proven-cold-email-frameworks-to-2-3x-your-reply-rates/): Proven cold email structures with examples and reply rate benchmarks. - [7 Steps to Building a Cold Email Campaign](https://yellowo.co.uk/the-7-steps-to-building-a-cold-email-campaign-in-the-right-order/): Step-by-step guide to campaign construction in the correct order. - [Interactive Outbound Sales Playbook](https://yellowo.co.uk/playbook.html): A live, searchable example of the playbook Yellow O delivers to clients. - [YouTube Channel](https://www.youtube.com/@MarkColgan): Strategy videos, tool walkthroughs, outbound teardowns, and over-the-shoulder demos. 1,400+ subscribers. - [20+ Free Resources](https://resources.yellowo.co.uk/): Covering everything from defining your ICP to writing cold emails that don't get deleted. Includes ICP and Persona Worksheet, Pain and Solution Map, SDR Quick Fix Guide, Effective Messages Guide, Problem-Focused Message Generator, Signal GTM Generator, Free Cold Email Course (5 modules), 5 Predictions for Outbound in 2026, Inbound/Outbound/Signals Guide, Why AI Underperforms in Sales, ABS Done Right, and Unhinged Follow-Up Generator. - [Outbound Sales Tools Directory](https://www.outboundsalestools.com/): 100+ B2B sales tools reviewed with expert video tutorials and unbiased opinions. ## Results - Parallax: $300,000 in new pipeline within 4 weeks, from zero outbound to a working engine. - Moss: Every coached SDR exceeded target and unlocked accelerator tier. - HiBob: Comprehensive global inbound and outbound audit with actionable recommendations grounded in real-world data and benchmarks, including a 92-94% reduction in speed-to-lead on the inbound side. - B2B SaaS client: 295% increase in net new MRR. - B2B SaaS client: 64% increase in closed-won deals in under 6 months. ## About Mark Colgan - [About](https://yellowo.co.uk/about/): Background, experience, approach, and credentials. - [Book a Call](https://yellowo.co.uk/schedule/): Schedule an outbound strategy call with Mark. - [LinkedIn](https://www.linkedin.com/in/outboundsalestech/): Mark Colgan's LinkedIn profile. - [YouTube](https://www.youtube.com/@MarkColgan): Strategy videos, tool walkthroughs, and outbound teardowns.